diff --git a/DeDRM_plugin/__init__.py b/DeDRM_plugin/__init__.py
index d2cbc2b..00640d1 100644
--- a/DeDRM_plugin/__init__.py
+++ b/DeDRM_plugin/__init__.py
@@ -7,7 +7,7 @@ from __future__ import with_statement
 # Copyright © 2008-2020 Apprentice Harper et al.
 
 __license__   = 'GPL v3'
-__version__ = '6.8.0'
+__version__ = '7.0.0'
 __docformat__ = 'restructuredtext en'
 
 
@@ -71,17 +71,19 @@ __docformat__ = 'restructuredtext en'
 #   6.6.3 - More cleanup of kindle book names and start of support for .kinf2018
 #   6.7.0 - Handle new library in calibre.
 #   6.8.0 - Full support for .kinf2018 and new KFX encryption (Kindle for PC/Mac 2.5+)
+#   7.0.0 - Switched to Python 3 for calibre 5.0. Thanks to all who comtibuted
 
 """
 Decrypt DRMed ebooks.
 """
 
 PLUGIN_NAME = u"DeDRM"
-PLUGIN_VERSION_TUPLE = (6, 8, 0)
+PLUGIN_VERSION_TUPLE = (7, 0, 0)
 PLUGIN_VERSION = u".".join([unicode(str(x)) for x in PLUGIN_VERSION_TUPLE])
 # Include an html helpfile in the plugin's zipfile with the following name.
 RESOURCE_NAME = PLUGIN_NAME + '_Help.htm'
 
+import codecs
 import sys, os, re
 import time
 import zipfile
@@ -107,7 +109,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         try:
             self.stream.write(data)
@@ -165,7 +167,7 @@ class DeDRM(FileTypePlugin):
                 else:
                     names = [u"libalfcrypto32.so",u"libalfcrypto64.so",u"kindlekey.py",u"adobekey.py",u"subasyncio.py"]
                 lib_dict = self.load_resources(names)
-                print u"{0} v{1}: Copying needed library files from plugin's zip".format(PLUGIN_NAME, PLUGIN_VERSION)
+                print("{0} v{1}: Copying needed library files from plugin's zip".format(PLUGIN_NAME, PLUGIN_VERSION))
 
                 for entry, data in lib_dict.items():
                     file_path = os.path.join(self.alfdir, entry)
@@ -177,7 +179,7 @@ class DeDRM(FileTypePlugin):
                     try:
                         open(file_path,'wb').write(data)
                     except:
-                        print u"{0} v{1}: Exception when copying needed library files".format(PLUGIN_NAME, PLUGIN_VERSION)
+                        print("{0} v{1}: Exception when copying needed library files".format(PLUGIN_NAME, PLUGIN_VERSION))
                         traceback.print_exc()
                         pass
 
@@ -187,7 +189,7 @@ class DeDRM(FileTypePlugin):
 
                 # mark that this version has been initialized
                 os.mkdir(self.verdir)
-        except Exception, e:
+        except Exception as e:
             traceback.print_exc()
             raise
 
@@ -198,11 +200,11 @@ class DeDRM(FileTypePlugin):
 
         inf = self.temporary_file(u".epub")
         try:
-            print u"{0} v{1}: Verifying zip archive integrity".format(PLUGIN_NAME, PLUGIN_VERSION)
+            print("{0} v{1}: Verifying zip archive integrity".format(PLUGIN_NAME, PLUGIN_VERSION))
             fr = zipfix.fixZip(path_to_ebook, inf.name)
             fr.fix()
-        except Exception, e:
-            print u"{0} v{1}: Error \'{2}\' when checking zip archive".format(PLUGIN_NAME, PLUGIN_VERSION, e.args[0])
+        except Exception as e:
+            print(u"{0} v{1}: Error \'{2}\' when checking zip archive".format(PLUGIN_NAME, PLUGIN_VERSION, e.args[0]))
             raise Exception(e)
 
         # import the decryption keys
@@ -215,19 +217,19 @@ class DeDRM(FileTypePlugin):
 
         #check the book
         if  ignobleepub.ignobleBook(inf.name):
-            print u"{0} v{1}: “{2}” is a secure Barnes & Noble ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook))
+            print("{0} v{1}: “{2}” is a secure Barnes & Noble ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
 
             # Attempt to decrypt epub with each encryption key (generated or provided).
             for keyname, userkey in dedrmprefs['bandnkeys'].items():
                 keyname_masked = u"".join((u'X' if (x.isdigit()) else x) for x in keyname)
-                print u"{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname_masked)
+                print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname_masked))
                 of = self.temporary_file(u".epub")
 
                 # Give the user key, ebook and TemporaryPersistent file to the decryption function.
                 try:
                     result = ignobleepub.decryptBook(userkey, inf.name, of.name)
                 except:
-                    print u"{0} v{1}: Exception when trying to decrypt after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                    print("{0} v{1}: Exception when trying to decrypt after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                     traceback.print_exc()
                     result = 1
 
@@ -238,10 +240,10 @@ class DeDRM(FileTypePlugin):
                     # Return the modified PersistentTemporary file to calibre.
                     return of.name
 
-                print u"{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime)
+                print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime))
 
             # perhaps we should see if we can get a key from a log file
-            print u"{0} v{1}: Looking for new NOOK Study Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+            print("{0} v{1}: Looking for new NOOK Study Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
             # get the default NOOK Study keys
             defaultkeys = []
@@ -258,7 +260,7 @@ class DeDRM(FileTypePlugin):
                     defaultkeys = WineGetKeys(scriptpath, u".b64",dedrmprefs['adobewineprefix'])
 
             except:
-                print u"{0} v{1}: Exception when getting default NOOK Study Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                print("{0} v{1}: Exception when getting default NOOK Study Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                 traceback.print_exc()
 
             newkeys = []
@@ -269,7 +271,7 @@ class DeDRM(FileTypePlugin):
             if len(newkeys) > 0:
                 try:
                     for i,userkey in enumerate(newkeys):
-                        print u"{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                        print("{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
 
                         of = self.temporary_file(u".epub")
 
@@ -277,7 +279,7 @@ class DeDRM(FileTypePlugin):
                         try:
                             result = ignobleepub.decryptBook(userkey, inf.name, of.name)
                         except:
-                           print u"{0} v{1}: Exception when trying to decrypt after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                           print("{0} v{1}: Exception when trying to decrypt after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                            traceback.print_exc()
                            result = 1
 
@@ -286,59 +288,59 @@ class DeDRM(FileTypePlugin):
                         if result == 0:
                             # Decryption was a success
                             # Store the new successful key in the defaults
-                            print u"{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                            print("{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                             try:
                                 dedrmprefs.addnamedvaluetoprefs('bandnkeys','nook_Study_key',keyvalue)
                                 dedrmprefs.writeprefs()
-                                print u"{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+                                print("{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                             except:
-                                print u"{0} v{1}: Exception saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                                print("{0} v{1}: Exception saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                                 traceback.print_exc()
                             # Return the modified PersistentTemporary file to calibre.
                             return of.name
 
-                        print u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
-                except Exception, e:
+                        print(u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
+                except Exception as e:
                     pass
 
-            print u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+            print("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
             raise DeDRMError(u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
         # import the Adobe Adept ePub handler
         import calibre_plugins.dedrm.ineptepub as ineptepub
 
         if ineptepub.adeptBook(inf.name):
-            print u"{0} v{1}: {2} is a secure Adobe Adept ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook))
+            print("{0} v{1}: {2} is a secure Adobe Adept ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
 
             # Attempt to decrypt epub with each encryption key (generated or provided).
             for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
-                userkey = userkeyhex.decode('hex')
-                print u"{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname)
+                userkey = codecs.decode(userkeyhex, 'hex')
+                print(u"{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
                 of = self.temporary_file(u".epub")
 
                 # Give the user key, ebook and TemporaryPersistent file to the decryption function.
                 try:
                     result = ineptepub.decryptBook(userkey, inf.name, of.name)
                 except:
-                    print u"{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                    print("{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                     traceback.print_exc()
                     result = 1
 
                 try:
                     of.close()
                 except:
-                    print u"{0} v{1}: Exception closing temporary file after {2:.1f} seconds. Ignored.".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                    print("{0} v{1}: Exception closing temporary file after {2:.1f} seconds. Ignored.".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
                 if  result == 0:
                     # Decryption was successful.
                     # Return the modified PersistentTemporary file to calibre.
-                    print u"{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime)
+                    print("{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
                     return of.name
 
-                print u"{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime)
+                print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
 
             # perhaps we need to get a new default ADE key
-            print u"{0} v{1}: Looking for new default Adobe Digital Editions Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+            print("{0} v{1}: Looking for new default Adobe Digital Editions Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
             # get the default Adobe keys
             defaultkeys = []
@@ -356,7 +358,7 @@ class DeDRM(FileTypePlugin):
 
                 self.default_key = defaultkeys[0]
             except:
-                print u"{0} v{1}: Exception when getting default Adobe Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                print("{0} v{1}: Exception when getting default Adobe Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                 traceback.print_exc()
                 self.default_key = u""
 
@@ -368,14 +370,14 @@ class DeDRM(FileTypePlugin):
             if len(newkeys) > 0:
                 try:
                     for i,userkey in enumerate(newkeys):
-                        print u"{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                        print("{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                         of = self.temporary_file(u".epub")
 
                         # Give the user key, ebook and TemporaryPersistent file to the decryption function.
                         try:
                             result = ineptepub.decryptBook(userkey, inf.name, of.name)
                         except:
-                            print u"{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                            print("{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                             traceback.print_exc()
                             result = 1
 
@@ -384,31 +386,31 @@ class DeDRM(FileTypePlugin):
                         if  result == 0:
                             # Decryption was a success
                             # Store the new successful key in the defaults
-                            print u"{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                            print("{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                             try:
                                 dedrmprefs.addnamedvaluetoprefs('adeptkeys','default_key',keyvalue.encode('hex'))
                                 dedrmprefs.writeprefs()
-                                print u"{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+                                print("{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                             except:
-                                print u"{0} v{1}: Exception when saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                                print("{0} v{1}: Exception when saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                                 traceback.print_exc()
-                            print u"{0} v{1}: Decrypted with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+                            print("{0} v{1}: Decrypted with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                             # Return the modified PersistentTemporary file to calibre.
                             return of.name
 
-                        print u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
-                except Exception, e:
-                    print u"{0} v{1}: Unexpected Exception trying a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                        print(u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
+                except Exception as e:
+                    print(u"{0} v{1}: Unexpected Exception trying a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                     traceback.print_exc()
                     pass
 
             # Something went wrong with decryption.
-            print u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+            print("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
             raise DeDRMError(u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
 
         # Not a Barnes & Noble nor an Adobe Adept
         # Import the fixed epub.
-        print u"{0} v{1}: “{2}” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook))
+        print("{0} v{1}: “{2}” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
         raise DeDRMError(u"{0} v{1}: Couldn't decrypt after {2:.1f} seconds. DRM free perhaps?".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
 
     def PDFDecrypt(self,path_to_ebook):
@@ -417,17 +419,17 @@ class DeDRM(FileTypePlugin):
 
         dedrmprefs = prefs.DeDRM_Prefs()
         # Attempt to decrypt epub with each encryption key (generated or provided).
-        print u"{0} v{1}: {2} is a PDF ebook".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook))
+        print("{0} v{1}: {2} is a PDF ebook".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
         for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
-            userkey = userkeyhex.decode('hex')
-            print u"{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname)
+            userkey = codecs.decode(userkeyhex, 'hex')
+            print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
             of = self.temporary_file(u".pdf")
 
             # Give the user key, ebook and TemporaryPersistent file to the decryption function.
             try:
                 result = ineptpdf.decryptBook(userkey, path_to_ebook, of.name)
             except:
-                print u"{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                print("{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                 traceback.print_exc()
                 result = 1
 
@@ -438,10 +440,10 @@ class DeDRM(FileTypePlugin):
                 # Return the modified PersistentTemporary file to calibre.
                 return of.name
 
-            print u"{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime)
+            print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
 
         # perhaps we need to get a new default ADE key
-        print u"{0} v{1}: Looking for new default Adobe Digital Editions Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+        print("{0} v{1}: Looking for new default Adobe Digital Editions Keys after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
         # get the default Adobe keys
         defaultkeys = []
@@ -459,7 +461,7 @@ class DeDRM(FileTypePlugin):
 
             self.default_key = defaultkeys[0]
         except:
-            print u"{0} v{1}: Exception when getting default Adobe Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+            print("{0} v{1}: Exception when getting default Adobe Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
             traceback.print_exc()
             self.default_key = u""
 
@@ -471,14 +473,14 @@ class DeDRM(FileTypePlugin):
         if len(newkeys) > 0:
             try:
                 for i,userkey in enumerate(newkeys):
-                    print u"{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                    print("{0} v{1}: Trying a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                     of = self.temporary_file(u".pdf")
 
                     # Give the user key, ebook and TemporaryPersistent file to the decryption function.
                     try:
                         result = ineptpdf.decryptBook(userkey, path_to_ebook, of.name)
                     except:
-                        print u"{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                        print("{0} v{1}: Exception when decrypting after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                         traceback.print_exc()
                         result = 1
 
@@ -487,23 +489,23 @@ class DeDRM(FileTypePlugin):
                     if  result == 0:
                         # Decryption was a success
                         # Store the new successful key in the defaults
-                        print u"{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION)
+                        print("{0} v{1}: Saving a new default key".format(PLUGIN_NAME, PLUGIN_VERSION))
                         try:
                             dedrmprefs.addnamedvaluetoprefs('adeptkeys','default_key',keyvalue.encode('hex'))
                             dedrmprefs.writeprefs()
-                            print u"{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+                            print("{0} v{1}: Saved a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                         except:
-                            print u"{0} v{1}: Exception when saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                            print("{0} v{1}: Exception when saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                             traceback.print_exc()
                         # Return the modified PersistentTemporary file to calibre.
                         return of.name
 
-                    print u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
-            except Exception, e:
+                    print(u"{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
+            except Exception as e:
                 pass
 
         # Something went wrong with decryption.
-        print u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+        print("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
         raise DeDRMError(u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
 
@@ -530,12 +532,12 @@ class DeDRM(FileTypePlugin):
 
         try:
             book = k4mobidedrm.GetDecryptedBook(path_to_ebook,kindleDatabases,androidFiles,serials,pids,self.starttime)
-        except Exception, e:
+        except Exception as e:
             decoded = False
             # perhaps we need to get a new default Kindle for Mac/PC key
             defaultkeys = []
-            print u"{0} v{1}: Failed to decrypt with error: {2}".format(PLUGIN_NAME, PLUGIN_VERSION,e.args[0])
-            print u"{0} v{1}: Looking for new default Kindle Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+            print("{0} v{1}: Failed to decrypt with error: {2}".format(PLUGIN_NAME, PLUGIN_VERSION,e.args[0]))
+            print("{0} v{1}: Looking for new default Kindle Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
             try:
                 if iswindows or isosx:
@@ -548,7 +550,7 @@ class DeDRM(FileTypePlugin):
                     scriptpath = os.path.join(self.alfdir,u"kindlekey.py")
                     defaultkeys = WineGetKeys(scriptpath, u".k4i",dedrmprefs['kindlewineprefix'])
             except:
-                print u"{0} v{1}: Exception when getting default Kindle Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime)
+                print("{0} v{1}: Exception when getting default Kindle Key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
                 traceback.print_exc()
                 pass
 
@@ -558,20 +560,20 @@ class DeDRM(FileTypePlugin):
                 if keyvalue not in dedrmprefs['kindlekeys'].values():
                     newkeys[keyname] = keyvalue
             if len(newkeys) > 0:
-                print u"{0} v{1}: Found {2} new {3}".format(PLUGIN_NAME, PLUGIN_VERSION, len(newkeys), u"key" if len(newkeys)==1 else u"keys")
+                print("{0} v{1}: Found {2} new {3}".format(PLUGIN_NAME, PLUGIN_VERSION, len(newkeys), u"key" if len(newkeys)==1 else u"keys"))
                 try:
                     book = k4mobidedrm.GetDecryptedBook(path_to_ebook,newkeys.items(),[],[],[],self.starttime)
                     decoded = True
                     # store the new successful keys in the defaults
-                    print u"{0} v{1}: Saving {2} new {3}".format(PLUGIN_NAME, PLUGIN_VERSION, len(newkeys), u"key" if len(newkeys)==1 else u"keys")
+                    print("{0} v{1}: Saving {2} new {3}".format(PLUGIN_NAME, PLUGIN_VERSION, len(newkeys), u"key" if len(newkeys)==1 else u"keys"))
                     for keyvalue in newkeys.values():
                         dedrmprefs.addnamedvaluetoprefs('kindlekeys','default_key',keyvalue)
                     dedrmprefs.writeprefs()
-                except Exception, e:
+                except Exception as e:
                     pass
             if not decoded:
                 #if you reached here then no luck raise and exception
-                print u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+                print("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
                 raise DeDRMError(u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
 
         of = self.temporary_file(book.getBookExtension())
@@ -590,7 +592,7 @@ class DeDRM(FileTypePlugin):
         # Attempt to decrypt epub with each encryption key (generated or provided).
         for keyname, userkey in dedrmprefs['ereaderkeys'].items():
             keyname_masked = u"".join((u'X' if (x.isdigit()) else x) for x in keyname)
-            print u"{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname_masked)
+            print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname_masked))
             of = self.temporary_file(u".pmlz")
 
             # Give the userkey, ebook and TemporaryPersistent file to the decryption function.
@@ -601,12 +603,12 @@ class DeDRM(FileTypePlugin):
             # Decryption was successful return the modified PersistentTemporary
             # file to Calibre's import process.
             if  result == 0:
-                print u"{0} v{1}: Successfully decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime)
+                print("{0} v{1}: Successfully decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime))
                 return of.name
 
-            print u"{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime)
+            print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime))
 
-        print u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+        print("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
         raise DeDRMError(u"{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
 
 
@@ -616,7 +618,7 @@ class DeDRM(FileTypePlugin):
         sys.stdout=SafeUnbuffered(sys.stdout)
         sys.stderr=SafeUnbuffered(sys.stderr)
 
-        print u"{0} v{1}: Trying to decrypt {2}".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook))
+        print("{0} v{1}: Trying to decrypt {2}".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
         self.starttime = time.time()
 
         booktype = os.path.splitext(path_to_ebook)[1].lower()[1:]
@@ -635,9 +637,9 @@ class DeDRM(FileTypePlugin):
             # Adobe Adept or B&N ePub
             decrypted_ebook = self.ePubDecrypt(path_to_ebook)
         else:
-            print u"Unknown booktype {0}. Passing back to calibre unchanged".format(booktype)
+            print("Unknown booktype {0}. Passing back to calibre unchanged".format(booktype))
             return path_to_ebook
-        print u"{0} v{1}: Finished after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime)
+        print("{0} v{1}: Finished after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
         return decrypted_ebook
 
     def is_customizable(self):
diff --git a/DeDRM_plugin/adobekey.py b/DeDRM_plugin/adobekey.py
index 2ede7c2..fb5dcca 100644
--- a/DeDRM_plugin/adobekey.py
+++ b/DeDRM_plugin/adobekey.py
@@ -48,14 +48,16 @@ from __future__ import with_statement
 #   5.8 - Added getkey interface for Windows DeDRM application
 #   5.9 - moved unicode_argv call inside main for Windows DeDRM compatibility
 #   6.0 - Work if TkInter is missing
+#   7.0 - Python 3 compatible for calibre 5
+
+from __future__ import print_function
 
 """
 Retrieve Adobe ADEPT user key.
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
-__version__ = '6.0'
+__version__ = '7.0'
 
 import sys, os, struct, getopt
 
@@ -118,7 +120,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return arg
 
 class ADEPTError(Exception):
     pass
@@ -497,7 +499,7 @@ def cli_main():
 
     try:
         opts, args = getopt.getopt(argv[1:], "h")
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
         print(u"Error in options or arguments: {0}".format(err.args[0]))
         usage(progname)
         sys.exit(2)
@@ -586,7 +588,7 @@ def gui_main():
                 keyfileout.write(key)
             success = True
             tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
-    except ADEPTError, e:
+    except ADEPTError as e:
         tkMessageBox.showerror(progname, u"Error: {0}".format(str(e)))
     except Exception:
         root.wm_state('normal')
diff --git a/DeDRM_plugin/aescbc.py b/DeDRM_plugin/aescbc.py
index 5667511..28e1843 100644
--- a/DeDRM_plugin/aescbc.py
+++ b/DeDRM_plugin/aescbc.py
@@ -13,6 +13,8 @@
     CryptoPy Artisitic License Version 1.0
     See the wonderful pure python package cryptopy-1.2.5
     and read its LICENSE.txt for complete license details.
+
+    Adjusted for Python 3 compatibility, September 2020
 """
 
 class CryptoError(Exception):
@@ -101,7 +103,7 @@ class BlockCipher:
         numBlocks, numExtraBytes = divmod(len(self.bytesToDecrypt), self.blockSize)
         if more == None:  # no more calls to decrypt, should have all the data
             if numExtraBytes  != 0:
-                raise DecryptNotBlockAlignedError, 'Data not block aligned on decrypt'
+                raise DecryptNotBlockAlignedError('Data not block aligned on decrypt')
 
         # hold back some bytes in case last decrypt has zero len
         if (more != None) and (numExtraBytes == 0) and (numBlocks >0) :
@@ -143,7 +145,7 @@ class padWithPadLen(Pad):
     def removePad(self, paddedBinaryString, blockSize):
         """ Remove padding from a binary string """
         if not(0<len(paddedBinaryString)):
-            raise DecryptNotBlockAlignedError, 'Expected More Data'
+            raise DecryptNotBlockAlignedError('Expected More Data')
         return paddedBinaryString[:-ord(paddedBinaryString[-1])]
 
 class noPadding(Pad):
@@ -451,7 +453,7 @@ class AES(Rijndael):
     def __init__(self, key = None, padding = padWithPadLen(), keySize=16):
         """ Initialize AES, keySize is in bytes """
         if  not (keySize == 16 or keySize == 24 or keySize == 32) :
-            raise BadKeySizeError, 'Illegal AES key size, must be 16, 24, or 32 bytes'
+            raise BadKeySizeError('Illegal AES key size, must be 16, 24, or 32 bytes')
 
         Rijndael.__init__( self, key, padding=padding, keySize=keySize, blockSize=16 )
 
diff --git a/DeDRM_plugin/alfcrypto.py b/DeDRM_plugin/alfcrypto.py
index 5d5e508..a5a11a5 100644
--- a/DeDRM_plugin/alfcrypto.py
+++ b/DeDRM_plugin/alfcrypto.py
@@ -178,13 +178,13 @@ def _load_python_alfcrypto():
             if len(key)!=16:
                 raise Exception('Pukall_Cipher: Bad key length.')
             wkey = []
-            for i in xrange(8):
+            for i in range(8):
                 wkey.append(ord(key[i*2])<<8 | ord(key[i*2+1]))
             dst = ""
-            for i in xrange(len(src)):
+            for i in range(len(src)):
                 temp1 = 0;
                 byteXorVal = 0;
-                for j in xrange(8):
+                for j in range(8):
                     temp1 ^= wkey[j]
                     sum2  = (sum2+j)*20021 + sum1
                     sum1  = (temp1*346)&0xFFFF
@@ -197,7 +197,7 @@ def _load_python_alfcrypto():
                 curByte = ((curByte ^ (byteXorVal >> 8)) ^ byteXorVal) & 0xFF
                 if decryption:
                     keyXorVal = curByte * 257;
-                for j in xrange(8):
+                for j in range(8):
                     wkey[j] ^= keyXorVal;
                 dst+=chr(curByte)
             return dst
diff --git a/DeDRM_plugin/androidkindlekey.py b/DeDRM_plugin/androidkindlekey.py
index a264c7d..f05c468 100644
--- a/DeDRM_plugin/androidkindlekey.py
+++ b/DeDRM_plugin/androidkindlekey.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
 # androidkindlekey.py
 # Copyright © 2013-15 by Thom and Apprentice Harper
@@ -17,14 +18,14 @@ from __future__ import with_statement
 #  1.3   - added in TkInter interface, output to a file
 #  1.4   - Fix some problems identified by Aldo Bleeker
 #  1.5   - Fix another problem identified by Aldo Bleeker
+#  2.0   - Add Python 3 compatibility
 
 """
 Retrieve Kindle for Android Serial Number.
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
-__version__ = '1.5'
+__version__ = '2.0'
 
 import os
 import sys
@@ -34,7 +35,10 @@ import tempfile
 import zlib
 import tarfile
 from hashlib import md5
-from cStringIO import StringIO
+try:
+    from cStringIO import StringIO
+except ImportError:
+    from io import BytesIO as StringIO
 from binascii import a2b_hex, b2a_hex
 
 # Routines common to Mac and PC
@@ -49,7 +53,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -90,7 +94,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"kindlekey.py"]
@@ -98,7 +102,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 class DrmException(Exception):
     pass
@@ -248,7 +252,7 @@ def get_serials2(path=STORAGE2):
             traceback.print_exc()
             pass
     tokens = list(set(tokens))
- 
+
     serials = []
     for x in dsns:
         serials.append(x)
@@ -313,7 +317,7 @@ __all__ = [ 'get_serials', 'getkey']
 def getkey(outfile, inpath):
     keys = get_serials(inpath)
     if len(keys) > 0:
-        with file(outfile, 'w') as keyfileout:
+        with open(outfile, 'w') as keyfileout:
             for key in keys:
                 keyfileout.write(key)
                 keyfileout.write("\n")
@@ -340,7 +344,7 @@ def cli_main():
 
     try:
         opts, args = getopt.getopt(argv[1:], "hb:")
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
         usage(progname)
         print(u"\nError in options or arguments: {0}".format(err.args[0]))
         return 2
@@ -444,11 +448,11 @@ def gui_main():
                         if not os.path.exists(outfile):
                             break
 
-                    with file(outfile, 'w') as keyfileout:
+                    with open(outfile, 'w') as keyfileout:
                         keyfileout.write(key)
                     success = True
                     tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
-            except Exception, e:
+            except Exception as e:
                 self.status['text'] = u"Error: {0}".format(e.args[0])
                 return
             self.status['text'] = u"Select backup.ab file"
diff --git a/DeDRM_plugin/argv_utils.py b/DeDRM_plugin/argv_utils.py
index 85ffaa4..71f0794 100644
--- a/DeDRM_plugin/argv_utils.py
+++ b/DeDRM_plugin/argv_utils.py
@@ -42,7 +42,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return arg
 
 
 def add_cp65001_codec():
diff --git a/DeDRM_plugin/askfolder_ed.py b/DeDRM_plugin/askfolder_ed.py
index a4a2ae0..1a85513 100644
--- a/DeDRM_plugin/askfolder_ed.py
+++ b/DeDRM_plugin/askfolder_ed.py
@@ -29,6 +29,8 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 # DEALINGS IN THE SOFTWARE.
 
+# Adjusted for Python 3, September 2020
+
 """
 AskFolder(...) -- Ask the user to select a folder Windows specific
 """
@@ -164,15 +166,15 @@ def AskFolder(
     def BrowseCallback(hwnd, uMsg, lParam, lpData):
         if uMsg == BFFM_INITIALIZED:
             if actionButtonLabel:
-                label = unicode(actionButtonLabel, errors='replace')
+                label = actionButtonLabel.decode('utf-8', 'replace')
                 user32.SendMessageW(hwnd, BFFM_SETOKTEXT, 0, label)
             if cancelButtonLabel:
-                label = unicode(cancelButtonLabel, errors='replace')
+                label = cancelButtonLabel.decode('utf-8', 'replace')
                 cancelButton = user32.GetDlgItem(hwnd, IDCANCEL)
                 if cancelButton:
                     user32.SetWindowTextW(cancelButton, label)
             if windowTitle:
-                title = unicode(windowTitle, erros='replace')
+                title = windowTitle.decode('utf-8', 'replace')
                 user32.SetWindowTextW(hwnd, title)
             if defaultLocation:
                 user32.SendMessageW(hwnd, BFFM_SETSELECTIONW, 1, defaultLocation.replace('/', '\\'))
diff --git a/DeDRM_plugin/config.py b/DeDRM_plugin/config.py
index 9bfae68..2ef3223 100644
--- a/DeDRM_plugin/config.py
+++ b/DeDRM_plugin/config.py
@@ -6,6 +6,8 @@ from __future__ import print_function
 
 __license__ = 'GPL v3'
 
+# Added Python 3 compatibility, September 2020
+
 # Standard Python modules.
 import os, traceback, json
 
@@ -22,7 +24,7 @@ try:
     from PyQt5 import Qt as QtGui
 except ImportError:
     from PyQt4 import QtGui
-    
+
 from zipfile import ZipFile
 
 # calibre modules and constants.
@@ -123,7 +125,7 @@ class ConfigWidget(QWidget):
     def kindle_serials(self):
         d = ManageKeysDialog(self,u"EInk Kindle Serial Number",self.tempdedrmprefs['serials'], AddSerialDialog)
         d.exec_()
-        
+
     def kindle_android(self):
         d = ManageKeysDialog(self,u"Kindle for Android Key",self.tempdedrmprefs['androidkeys'], AddAndroidDialog, 'k4a')
         d.exec_()
@@ -289,7 +291,7 @@ class ManageKeysDialog(QDialog):
 
     def getwineprefix(self):
         if self.wineprefix is not None:
-            return unicode(self.wp_lineedit.text()).strip()
+            return self.wp_lineedit.text().strip()
         return u""
 
     def populate_list(self):
@@ -338,7 +340,7 @@ class ManageKeysDialog(QDialog):
         if d.result() != d.Accepted:
             # rename cancelled or moot.
             return
-        keyname = unicode(self.listy.currentItem().text())
+        keyname = self.listy.currentItem().text()
         if not question_dialog(self, "{0} {1}: Confirm Rename".format(PLUGIN_NAME, PLUGIN_VERSION), u"Do you really want to rename the {2} named <strong>{0}</strong> to <strong>{1}</strong>?".format(keyname,d.key_name,self.key_type_name), show_copy_button=False, default_yes=False):
             return
         self.plugin_keys[d.key_name] = self.plugin_keys[keyname]
@@ -350,7 +352,7 @@ class ManageKeysDialog(QDialog):
     def delete_key(self):
         if not self.listy.currentItem():
             return
-        keyname = unicode(self.listy.currentItem().text())
+        keyname = self.listy.currentItem().text()
         if not question_dialog(self, "{0} {1}: Confirm Delete".format(PLUGIN_NAME, PLUGIN_VERSION), u"Do you really want to delete the {1} <strong>{0}</strong>?".format(keyname, self.key_type_name), show_copy_button=False, default_yes=False):
             return
         if type(self.plugin_keys) == dict:
@@ -388,7 +390,7 @@ class ManageKeysDialog(QDialog):
                 with open(fpath,'rb') as keyfile:
                     new_key_value = keyfile.read()
                 if self.binary_file:
-                    new_key_value = new_key_value.encode('hex')
+                    new_key_value = new_key_value.hex()
                 elif self.json_file:
                     new_key_value = json.loads(new_key_value)
                 elif self.android_file:
@@ -412,7 +414,7 @@ class ManageKeysDialog(QDialog):
                     else:
                         counter += 1
                         self.plugin_keys[new_key_name] = new_key_value
-                            
+
             msg = u""
             if counter+skipped > 1:
                 if counter > 0:
@@ -434,7 +436,7 @@ class ManageKeysDialog(QDialog):
             r = error_dialog(None, "{0} {1}".format(PLUGIN_NAME, PLUGIN_VERSION),
                                     _(errmsg), show=True, show_copy_button=False)
             return
-        keyname = unicode(self.listy.currentItem().text())
+        keyname = self.listy.currentItem().text()
         unique_dlg_name = PLUGIN_NAME + u"export {0} keys".format(self.key_type_name).replace(' ', '_') #takes care of automatically remembering last directory
         caption = u"Save {0} File as...".format(self.key_type_name)
         filters = [(u"{0} Files".format(self.key_type_name), [u"{0}".format(self.keyfile_ext)])]
@@ -485,7 +487,7 @@ class RenameKeyDialog(QDialog):
         self.resize(self.sizeHint())
 
     def accept(self):
-        if not unicode(self.key_ledit.text()) or unicode(self.key_ledit.text()).isspace():
+        if not self.key_ledit.text() or self.key_ledit.text().isspace():
             errmsg = u"Key name field cannot be empty!"
             return error_dialog(None, "{0} {1}".format(PLUGIN_NAME, PLUGIN_VERSION),
                                     _(errmsg), show=True, show_copy_button=False)
@@ -506,7 +508,7 @@ class RenameKeyDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
 
 
@@ -589,19 +591,19 @@ class AddBandNKeyDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
-        return unicode(self.key_display.text()).strip()
+        return self.key_display.text().strip()
 
     @property
     def user_name(self):
-        return unicode(self.name_ledit.text()).strip().lower().replace(' ','')
+        return self.name_ledit.text().strip().lower().replace(' ','')
 
     @property
     def cc_number(self):
-        return unicode(self.cc_ledit.text()).strip()
+        return self.cc_ledit.text().strip()
 
     def retrieve_key(self):
         from calibre_plugins.dedrm.ignoblekeyfetch import fetch_key as fetch_bandn_key
@@ -675,7 +677,7 @@ class AddEReaderDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
@@ -684,11 +686,11 @@ class AddEReaderDialog(QDialog):
 
     @property
     def user_name(self):
-        return unicode(self.name_ledit.text()).strip().lower().replace(' ','')
+        return self.name_ledit.text().strip().lower().replace(' ','')
 
     @property
     def cc_number(self):
-        return unicode(self.cc_ledit.text()).strip().replace(' ', '').replace('-','')
+        return self.cc_ledit.text().strip().replace(' ', '').replace('-','')
 
 
     def accept(self):
@@ -758,7 +760,7 @@ class AddAdeptDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
@@ -819,7 +821,7 @@ class AddKindleDialog(QDialog):
             default_key_error = QLabel(u"The default encryption key for Kindle for Mac/PC could not be found.", self)
             default_key_error.setAlignment(Qt.AlignHCenter)
             layout.addWidget(default_key_error)
-            
+
             # if no default, both buttons do the same
             self.button_box.accepted.connect(self.reject)
 
@@ -830,7 +832,7 @@ class AddKindleDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
@@ -876,11 +878,11 @@ class AddSerialDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
-        return unicode(self.key_ledit.text()).replace(' ', '')
+        return self.key_ledit.text().replace(' ', '')
 
     def accept(self):
         if len(self.key_name) == 0 or self.key_name.isspace():
@@ -916,7 +918,7 @@ class AddAndroidDialog(QDialog):
         self.selected_file_name = QLabel(u"",self)
         self.selected_file_name.setAlignment(Qt.AlignHCenter)
         file_group.addWidget(self.selected_file_name)
-        
+
         key_group = QHBoxLayout()
         data_group_box_layout.addLayout(key_group)
         key_group.addWidget(QLabel(u"Unique Key Name:", self))
@@ -926,7 +928,7 @@ class AddAndroidDialog(QDialog):
         #key_label = QLabel(_(''), self)
         #key_label.setAlignment(Qt.AlignHCenter)
         #data_group_box_layout.addWidget(key_label)
-        
+
         self.button_box.accepted.connect(self.accept)
         self.button_box.rejected.connect(self.reject)
         layout.addWidget(self.button_box)
@@ -934,16 +936,16 @@ class AddAndroidDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def file_name(self):
-        return unicode(self.selected_file_name.text()).strip()
+        return self.selected_file_name.text().strip()
 
     @property
     def key_value(self):
         return self.serials_from_file
-        
+
     def get_android_file(self):
         unique_dlg_name = PLUGIN_NAME + u"Import Kindle for Android backup file" #takes care of automatically remembering last directory
         caption = u"Select Kindle for Android backup file to add"
@@ -961,7 +963,7 @@ class AddAndroidDialog(QDialog):
                     file_name = os.path.basename(self.filename)
                     self.serials_from_file.extend(file_serials)
         self.selected_file_name.setText(file_name)
-    
+
 
     def accept(self):
         if len(self.file_name) == 0 or len(self.key_value) == 0:
@@ -1004,11 +1006,11 @@ class AddPIDDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     def accept(self):
         if len(self.key_name) == 0 or self.key_name.isspace():
diff --git a/DeDRM_plugin/convert2xml.py b/DeDRM_plugin/convert2xml.py
index 3b65c54..aa794b1 100644
--- a/DeDRM_plugin/convert2xml.py
+++ b/DeDRM_plugin/convert2xml.py
@@ -1,6 +1,7 @@
 #! /usr/bin/python
 # vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab
 # For use with Topaz Scripts Version 2.6
+# Added Python 3 compatibility, September 2020
 
 from __future__ import print_function
 class Unbuffered:
@@ -107,7 +108,7 @@ def readString(file):
 def convert(i):
     result = ''
     val = encodeNumber(i)
-    for j in xrange(len(val)):
+    for j in range(len(val)):
         c = ord(val[j:j+1])
         result += '%02x' % c
     return result
@@ -121,10 +122,10 @@ class Dictionary(object):
     def __init__(self, dictFile):
         self.filename = dictFile
         self.size = 0
-        self.fo = file(dictFile,'rb')
+        self.fo = open(dictFile,'rb')
         self.stable = []
         self.size = readEncodedNumber(self.fo)
-        for i in xrange(self.size):
+        for i in range(self.size):
             self.stable.append(self.escapestr(readString(self.fo)))
         self.pos = 0
 
@@ -151,7 +152,7 @@ class Dictionary(object):
         return self.pos
 
     def dumpDict(self):
-        for i in xrange(self.size):
+        for i in range(self.size):
             print("%d %s %s" % (i, convert(i), self.stable[i]))
         return
 
@@ -161,7 +162,7 @@ class Dictionary(object):
 
 class PageParser(object):
     def __init__(self, filename, dict, debug, flat_xml):
-        self.fo = file(filename,'rb')
+        self.fo = open(filename,'rb')
         self.id = os.path.basename(filename).replace('.dat','')
         self.dict = dict
         self.debug = debug
@@ -392,7 +393,7 @@ class PageParser(object):
         'startID'      : (0, 'number', 1, 1),
         'startID.page' : (1, 'number', 0, 0),
         'startID.id'   : (1, 'number', 0, 0),
-    
+
         'median_d'          : (1, 'number', 0, 0),
         'median_h'          : (1, 'number', 0, 0),
         'median_firsty'     : (1, 'number', 0, 0),
@@ -420,7 +421,7 @@ class PageParser(object):
     def get_tagpath(self, i):
         cnt = len(self.tagpath)
         if i < cnt : result = self.tagpath[i]
-        for j in xrange(i+1, cnt) :
+        for j in range(i+1, cnt) :
             result += '.' + self.tagpath[j]
         return result
 
@@ -472,7 +473,7 @@ class PageParser(object):
 
         if self.debug : print('Processing: ', self.get_tagpath(0))
         cnt = self.tagpath_len()
-        for j in xrange(cnt):
+        for j in range(cnt):
             tkn = self.get_tagpath(j)
             if tkn in self.token_tags :
                 num_args = self.token_tags[tkn][0]
@@ -497,7 +498,7 @@ class PageParser(object):
             if (subtags == 1):
                 ntags = readEncodedNumber(self.fo)
                 if self.debug : print('subtags: ' + token + ' has ' + str(ntags))
-                for j in xrange(ntags):
+                for j in range(ntags):
                     val = readEncodedNumber(self.fo)
                     subtagres.append(self.procToken(self.dict.lookup(val)))
 
@@ -511,7 +512,7 @@ class PageParser(object):
                     argres = self.decodeCMD(arg,argtype)
                 else :
                     # num_arg scalar arguments
-                    for i in xrange(num_args):
+                    for i in range(num_args):
                         argres.append(self.formatArg(readEncodedNumber(self.fo), argtype))
 
             # build the return tag
@@ -546,7 +547,7 @@ class PageParser(object):
             result += 'of the document is indicated by snippet number sets at the\n'
             result += 'end of each snippet. \n'
             print(result)
-        for i in xrange(cnt):
+        for i in range(cnt):
             if self.debug: print('Snippet:',str(i))
             snippet = []
             snippet.append(i)
@@ -565,12 +566,12 @@ class PageParser(object):
             adj = readEncodedNumber(self.fo)
         mode = mode >> 1
         x = []
-        for i in xrange(cnt):
+        for i in range(cnt):
             x.append(readEncodedNumber(self.fo) - adj)
-        for i in xrange(mode):
-            for j in xrange(1, cnt):
+        for i in range(mode):
+            for j in range(1, cnt):
                 x[j] = x[j] + x[j - 1]
-        for i in xrange(cnt):
+        for i in range(cnt):
             result.append(self.formatArg(x[i],argtype))
         return result
 
@@ -844,7 +845,7 @@ def main(argv):
     try:
         opts, args = getopt.getopt(argv[1:], "hd", ["flat-xml"])
 
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
 
         # print help information and exit:
         print(str(err)) # will print something like "option -a not recognized"
diff --git a/DeDRM_plugin/epubtest.py b/DeDRM_plugin/epubtest.py
index 2b00fe7..1a08e61 100644
--- a/DeDRM_plugin/epubtest.py
+++ b/DeDRM_plugin/epubtest.py
@@ -10,6 +10,7 @@
 # Changelog epubtest
 #  1.00 - Cut to epubtest.py, testing ePub files only by Apprentice Alf
 #  1.01 - Added routine for use by Windows DeDRM
+#  2.00 - Added Python 3 compatibility, September 2020
 #
 # Written in 2011 by Paul Durrant
 # Released with unlicense. See http://unlicense.org/
@@ -47,7 +48,7 @@
 from __future__ import with_statement
 from __future__ import print_function
 
-__version__ = '1.01'
+__version__ = '2.0'
 
 import sys, struct, os, traceback
 import zlib
@@ -116,7 +117,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return arg
 
 _FILENAME_LEN_OFFSET = 26
 _EXTRA_LEN_OFFSET = 28
diff --git a/DeDRM_plugin/erdr2pml.py b/DeDRM_plugin/erdr2pml.py
index 1dfef42..b02a494 100644
--- a/DeDRM_plugin/erdr2pml.py
+++ b/DeDRM_plugin/erdr2pml.py
@@ -67,8 +67,9 @@
 #       - Ignore sidebars for dictionaries (different format?)
 #  0.22 - Unicode and plugin support, different image folders for PMLZ and source
 #  0.23 - moved unicode_argv call inside main for Windows DeDRM compatibility
+#  1.00 - Added Python 3 compatibility for calibre 5.0
 
-__version__='0.23'
+__version__='1.00'
 
 import sys, re
 import struct, binascii, getopt, zlib, os, os.path, urllib, tempfile, traceback
@@ -88,7 +89,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -126,7 +127,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"mobidedrm.py"]
@@ -134,7 +135,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 Des = None
 if iswindows:
@@ -200,7 +201,7 @@ class Sectionizer(object):
     bkType = "Book"
 
     def __init__(self, filename, ident):
-        self.contents = file(filename, 'rb').read()
+        self.contents = open(filename, 'rb').read()
         self.header = self.contents[0:72]
         self.num_sections, = struct.unpack('>H', self.contents[76:78])
         # Dictionary or normal content (TODO: Not hard-coded)
@@ -210,7 +211,7 @@ class Sectionizer(object):
             else:
                 raise ValueError('Invalid file format')
         self.sections = []
-        for i in xrange(self.num_sections):
+        for i in range(self.num_sections):
             offset, a1,a2,a3,a4 = struct.unpack('>LBBBB', self.contents[78+i*8:78+i*8+8])
             flags, val = a1, a2<<16|a3<<8|a4
             self.sections.append( (offset, flags, val) )
@@ -233,7 +234,7 @@ def sanitizeFileName(name):
     # delete control characters
     name = u"".join(char for char in name if ord(char)>=32)
     # white space to single space, delete leading and trailing while space
-    name = re.sub(ur"\s", u" ", name).strip()
+    name = re.sub(r"\s", u" ", name).strip()
     # remove leading dots
     while len(name)>0 and name[0] == u".":
         name = name[1:]
@@ -250,7 +251,7 @@ def fixKey(key):
 def deXOR(text, sp, table):
     r=''
     j = sp
-    for i in xrange(len(text)):
+    for i in range(len(text)):
         r += chr(ord(table[j]) ^ ord(text[i]))
         j = j + 1
         if j == len(table):
@@ -276,7 +277,7 @@ class EreaderProcessor(object):
         def unshuff(data, shuf):
             r = [''] * len(data)
             j = 0
-            for i in xrange(len(data)):
+            for i in range(len(data)):
                 j = (j + shuf) % len(data)
                 r[j] = data[i]
             assert    len("".join(r)) == len(data)
@@ -330,7 +331,7 @@ class EreaderProcessor(object):
         self.flags = struct.unpack('>L', r[4:8])[0]
         reqd_flags = (1<<9) | (1<<7) | (1<<10)
         if (self.flags & reqd_flags) != reqd_flags:
-            print "Flags: 0x%X" % self.flags
+            print("Flags: 0x%X" % self.flags)
             raise ValueError('incompatible eReader file')
         des = Des(fixKey(user_key))
         if version == 259:
@@ -361,7 +362,7 @@ class EreaderProcessor(object):
         sect = self.section_reader(self.first_image_page + i)
         name = sect[4:4+32].strip('\0')
         data = sect[62:]
-        return sanitizeFileName(unicode(name,'windows-1252')), data
+        return sanitizeFileName(name.decode('windows-1252')), data
 
 
     # def getChapterNamePMLOffsetData(self):
@@ -410,7 +411,7 @@ class EreaderProcessor(object):
     def getText(self):
         des = Des(fixKey(self.content_key))
         r = ''
-        for i in xrange(self.num_text_pages):
+        for i in range(self.num_text_pages):
             logging.debug('get page %d', i)
             r += zlib.decompress(des.decrypt(self.section_reader(1 + i)))
 
@@ -422,7 +423,7 @@ class EreaderProcessor(object):
             fnote_ids = deXOR(sect, 0, self.xortable)
             # the remaining records of the footnote sections need to be decoded with the content_key and zlib inflated
             des = Des(fixKey(self.content_key))
-            for i in xrange(1,self.num_footnote_pages):
+            for i in range(1,self.num_footnote_pages):
                 logging.debug('get footnotepage %d', i)
                 id_len = ord(fnote_ids[2])
                 id = fnote_ids[3:3+id_len]
@@ -446,7 +447,7 @@ class EreaderProcessor(object):
             sbar_ids = deXOR(sect, 0, self.xortable)
             # the remaining records of the sidebar sections need to be decoded with the content_key and zlib inflated
             des = Des(fixKey(self.content_key))
-            for i in xrange(1,self.num_sidebar_pages):
+            for i in range(1,self.num_sidebar_pages):
                 id_len = ord(sbar_ids[2])
                 id = sbar_ids[3:3+id_len]
                 smarker = '<sidebar id="%s">\n' % id
@@ -460,7 +461,7 @@ class EreaderProcessor(object):
 def cleanPML(pml):
     # Convert special characters to proper PML code.  High ASCII start at (\x80, \a128) and go up to (\xff, \a255)
     pml2 = pml
-    for k in xrange(128,256):
+    for k in range(128,256):
         badChar = chr(k)
         pml2 = pml2.replace(badChar, '\\a%03d' % k)
     return pml2
@@ -480,26 +481,26 @@ def decryptBook(infile, outpath, make_pmlz, user_key):
     try:
         if not os.path.exists(outdir):
             os.makedirs(outdir)
-        print u"Decoding File"
+        print(u"Decoding File")
         sect = Sectionizer(infile, 'PNRdPPrs')
         er = EreaderProcessor(sect, user_key)
 
         if er.getNumImages() > 0:
-            print u"Extracting images"
+            print(u"Extracting images")
             if not os.path.exists(imagedirpath):
                 os.makedirs(imagedirpath)
-            for i in xrange(er.getNumImages()):
+            for i in range(er.getNumImages()):
                 name, contents = er.getImage(i)
-                file(os.path.join(imagedirpath, name), 'wb').write(contents)
+                open(os.path.join(imagedirpath, name), 'wb').write(contents)
 
-        print u"Extracting pml"
+        print(u"Extracting pml")
         pml_string = er.getText()
         pmlfilename = bookname + ".pml"
-        file(os.path.join(outdir, pmlfilename),'wb').write(cleanPML(pml_string))
+        open(os.path.join(outdir, pmlfilename),'wb').write(cleanPML(pml_string))
         if pmlzname is not None:
             import zipfile
             import shutil
-            print u"Creating PMLZ file {0}".format(os.path.basename(pmlzname))
+            print(u"Creating PMLZ file {0}".format(os.path.basename(pmlzname)))
             myZipFile = zipfile.ZipFile(pmlzname,'w',zipfile.ZIP_STORED, False)
             list = os.listdir(outdir)
             for filename in list:
@@ -518,33 +519,33 @@ def decryptBook(infile, outpath, make_pmlz, user_key):
             myZipFile.close()
             # remove temporary directory
             shutil.rmtree(outdir, True)
-            print u"Output is {0}".format(pmlzname)
+            print(u"Output is {0}".format(pmlzname))
         else :
-            print u"Output is in {0}".format(outdir)
-        print "done"
-    except ValueError, e:
-        print u"Error: {0}".format(e)
+            print(u"Output is in {0}".format(outdir))
+        print("done")
+    except ValueError as e:
+        print(u"Error: {0}".format(e))
         traceback.print_exc()
         return 1
     return 0
 
 
 def usage():
-    print u"Converts DRMed eReader books to PML Source"
-    print u"Usage:"
-    print u"  erdr2pml [options] infile.pdb [outpath] \"your name\" credit_card_number"
-    print u" "
-    print u"Options: "
-    print u"  -h             prints this message"
-    print u"  -p             create PMLZ instead of source folder"
-    print u"  --make-pmlz    create PMLZ instead of source folder"
-    print u" "
-    print u"Note:"
-    print u"  if outpath is ommitted, creates source in 'infile_Source' folder"
-    print u"  if outpath is ommitted and pmlz option, creates PMLZ 'infile.pmlz'"
-    print u"  if source folder created, images are in infile_img folder"
-    print u"  if pmlz file created, images are in images folder"
-    print u"  It's enough to enter the last 8 digits of the credit card number"
+    print(u"Converts DRMed eReader books to PML Source")
+    print(u"Usage:")
+    print(u"  erdr2pml [options] infile.pdb [outpath] \"your name\" credit_card_number")
+    print(u" ")
+    print(u"Options: ")
+    print(u"  -h             prints this message")
+    print(u"  -p             create PMLZ instead of source folder")
+    print(u"  --make-pmlz    create PMLZ instead of source folder")
+    print(u" ")
+    print(u"Note:")
+    print(u"  if outpath is ommitted, creates source in 'infile_Source' folder")
+    print(u"  if outpath is ommitted and pmlz option, creates PMLZ 'infile.pmlz'")
+    print(u"  if source folder created, images are in infile_img folder")
+    print(u"  if pmlz file created, images are in images folder")
+    print(u"  It's enough to enter the last 8 digits of the credit card number")
     return
 
 def getuser_key(name,cc):
@@ -553,13 +554,13 @@ def getuser_key(name,cc):
     return struct.pack('>LL', binascii.crc32(newname) & 0xffffffff,binascii.crc32(cc[-8:])& 0xffffffff)
 
 def cli_main():
-    print u"eRdr2Pml v{0}. Copyright © 2009–2012 The Dark Reverser et al.".format(__version__)
+    print(u"eRdr2Pml v{0}. Copyright © 2009–2012 The Dark Reverser et al.".format(__version__))
 
     argv=unicode_argv()
     try:
         opts, args = getopt.getopt(argv[1:], "hp", ["make-pmlz"])
-    except getopt.GetoptError, err:
-        print err.args[0]
+    except getopt.GetoptError as err:
+        print(err.args[0])
         usage()
         return 1
     make_pmlz = False
@@ -585,7 +586,7 @@ def cli_main():
     elif len(args)==4:
         infile, outpath, name, cc = args
 
-    print getuser_key(name,cc).encode('hex')
+    print(getuser_key(name,cc).encode('hex'))
 
     return decryptBook(infile, outpath, make_pmlz, getuser_key(name,cc))
 
diff --git a/DeDRM_plugin/genbook.py b/DeDRM_plugin/genbook.py
index a7512af..6667e49 100644
--- a/DeDRM_plugin/genbook.py
+++ b/DeDRM_plugin/genbook.py
@@ -1,5 +1,6 @@
 #! /usr/bin/python
 # vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab
+# Added Python 3 compatibility for calibre 5.0
 
 from __future__ import print_function
 from .convert2xml import encodeNumber
@@ -87,9 +88,9 @@ def readString(file):
 def getMetaArray(metaFile):
     # parse the meta file
     result = {}
-    fo = file(metaFile,'rb')
+    fo = open(metaFile,'rb')
     size = readEncodedNumber(fo)
-    for i in xrange(size):
+    for i in range(size):
         tag = readString(fo)
         value = readString(fo)
         result[tag] = value
@@ -103,10 +104,10 @@ class Dictionary(object):
     def __init__(self, dictFile):
         self.filename = dictFile
         self.size = 0
-        self.fo = file(dictFile,'rb')
+        self.fo = open(dictFile,'rb')
         self.stable = []
         self.size = readEncodedNumber(self.fo)
-        for i in xrange(self.size):
+        for i in range(self.size):
             self.stable.append(self.escapestr(readString(self.fo)))
         self.pos = 0
     def escapestr(self, str):
@@ -142,7 +143,7 @@ class PageDimParser(object):
         else:
             end = min(cnt,end)
         foundat = -1
-        for j in xrange(pos, end):
+        for j in range(pos, end):
             item = docList[j]
             if item.find('=') >= 0:
                 (name, argres) = item.split('=')
@@ -195,7 +196,7 @@ class GParser(object):
     def getData(self, path):
         result = None
         cnt = len(self.flatdoc)
-        for j in xrange(cnt):
+        for j in range(cnt):
             item = self.flatdoc[j]
             if item.find('=') >= 0:
                 (name, argt) = item.split('=')
@@ -207,7 +208,7 @@ class GParser(object):
                 result = argres
                 break
         if (len(argres) > 0) :
-            for j in xrange(0,len(argres)):
+            for j in range(0,len(argres)):
                 argres[j] = int(argres[j])
         return result
     def getGlyphDim(self, gly):
@@ -223,7 +224,7 @@ class GParser(object):
         tx = self.vx[self.gvtx[gly]:self.gvtx[gly+1]]
         ty = self.vy[self.gvtx[gly]:self.gvtx[gly+1]]
         p = 0
-        for k in xrange(self.glen[gly], self.glen[gly+1]):
+        for k in range(self.glen[gly], self.glen[gly+1]):
             if (p == 0):
                 zx = tx[0:self.vlen[k]+1]
                 zy = ty[0:self.vlen[k]+1]
@@ -322,17 +323,17 @@ def generateBook(bookDir, raw, fixedimage):
         imgname = filename.replace('color','img')
         sfile = os.path.join(spath,filename)
         dfile = os.path.join(dpath,imgname)
-        imgdata = file(sfile,'rb').read()
-        file(dfile,'wb').write(imgdata)
+        imgdata = open(sfile,'rb').read()
+        open(dfile,'wb').write(imgdata)
 
     print("Creating cover.jpg")
     isCover = False
     cpath = os.path.join(bookDir,'img')
     cpath = os.path.join(cpath,'img0000.jpg')
     if os.path.isfile(cpath):
-        cover = file(cpath, 'rb').read()
+        cover = open(cpath, 'rb').read()
         cpath = os.path.join(bookDir,'cover.jpg')
-        file(cpath, 'wb').write(cover)
+        open(cpath, 'wb').write(cover)
         isCover = True
 
 
@@ -361,7 +362,7 @@ def generateBook(bookDir, raw, fixedimage):
             mlst.append('<meta name="' + key + '" content="' + meta_array[key] + '" />\n')
         metastr = "".join(mlst)
         mlst = None
-        file(xname, 'wb').write(metastr)
+        open(xname, 'wb').write(metastr)
 
     print('Processing StyleSheet')
 
@@ -424,10 +425,10 @@ def generateBook(bookDir, raw, fixedimage):
 
     # now get the css info
     cssstr , classlst = stylexml2css.convert2CSS(flat_xml, fontsize, ph, pw)
-    file(xname, 'wb').write(cssstr)
+    open(xname, 'wb').write(cssstr)
     if buildXML:
         xname = os.path.join(xmlDir, 'other0000.xml')
-        file(xname, 'wb').write(convert2xml.getXML(dict, otherFile))
+        open(xname, 'wb').write(convert2xml.getXML(dict, otherFile))
 
     print('Processing Glyphs')
     gd = GlyphDict()
@@ -449,10 +450,10 @@ def generateBook(bookDir, raw, fixedimage):
 
         if buildXML:
             xname = os.path.join(xmlDir, filename.replace('.dat','.xml'))
-            file(xname, 'wb').write(convert2xml.getXML(dict, fname))
+            open(xname, 'wb').write(convert2xml.getXML(dict, fname))
 
         gp = GParser(flat_xml)
-        for i in xrange(0, gp.count):
+        for i in range(0, gp.count):
             path = gp.getPath(i)
             maxh, maxw = gp.getGlyphDim(i)
             fullpath = '<path id="gl%d" d="%s" fill="black" /><!-- width=%d height=%d -->\n' % (counter * 256 + i, path, maxw, maxh)
@@ -507,7 +508,7 @@ def generateBook(bookDir, raw, fixedimage):
 
         if buildXML:
             xname = os.path.join(xmlDir, filename.replace('.dat','.xml'))
-            file(xname, 'wb').write(convert2xml.getXML(dict, fname))
+            open(xname, 'wb').write(convert2xml.getXML(dict, fname))
 
         # first get the html
         pagehtml, tocinfo = flatxml2html.convert2HTML(flat_xml, classlst, fname, bookDir, gd, fixedimage)
@@ -518,7 +519,7 @@ def generateBook(bookDir, raw, fixedimage):
     hlst.append('</body>\n</html>\n')
     htmlstr = "".join(hlst)
     hlst = None
-    file(os.path.join(bookDir, htmlFileName), 'wb').write(htmlstr)
+    open(os.path.join(bookDir, htmlFileName), 'wb').write(htmlstr)
 
     print(" ")
     print('Extracting Table of Contents from Amazon OCR')
@@ -564,7 +565,7 @@ def generateBook(bookDir, raw, fixedimage):
     tlst.append('</body>\n')
     tlst.append('</html>\n')
     tochtml = "".join(tlst)
-    file(os.path.join(svgDir, 'toc.xhtml'), 'wb').write(tochtml)
+    open(os.path.join(svgDir, 'toc.xhtml'), 'wb').write(tochtml)
 
 
     # now create index_svg.xhtml that points to all required files
@@ -619,7 +620,7 @@ def generateBook(bookDir, raw, fixedimage):
     slst.append('</body>\n</html>\n')
     svgindex = "".join(slst)
     slst = None
-    file(os.path.join(bookDir, 'index_svg.xhtml'), 'wb').write(svgindex)
+    open(os.path.join(bookDir, 'index_svg.xhtml'), 'wb').write(svgindex)
 
     print(" ")
 
@@ -668,7 +669,7 @@ def generateBook(bookDir, raw, fixedimage):
     olst.append('</package>\n')
     opfstr = "".join(olst)
     olst = None
-    file(opfname, 'wb').write(opfstr)
+    open(opfname, 'wb').write(opfstr)
 
     print('Processing Complete')
 
@@ -694,7 +695,7 @@ def main(argv):
     try:
         opts, args = getopt.getopt(argv[1:], "rh:",["fixed-image"])
 
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
         print(str(err))
         usage()
         return 1
diff --git a/DeDRM_plugin/ignobleepub.py b/DeDRM_plugin/ignobleepub.py
index c16d88b..9ec9459 100644
--- a/DeDRM_plugin/ignobleepub.py
+++ b/DeDRM_plugin/ignobleepub.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
 # ignobleepub.pyw, version 4.1
 # Copyright © 2009-2010 by i♥cabbages
@@ -37,14 +38,14 @@ from __future__ import with_statement
 #   3.9 - moved unicode_argv call inside main for Windows DeDRM compatibility
 #   4.0 - Work if TkInter is missing
 #   4.1 - Import tkFileDialog, don't assume something else will import it.
+#   5.0 - Added Python 3 compatibility for calibre 5.0
 
 """
 Decrypt Barnes & Noble encrypted ePub books.
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
-__version__ = "4.1"
+__version__ = "5.0"
 
 import sys
 import os
@@ -65,7 +66,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -106,13 +107,13 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         return [u"ineptepub.py"]
     else:
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 
 class IGNOBLEError(Exception):
@@ -434,7 +435,7 @@ def gui_main():
             self.status['text'] = u"Decrypting..."
             try:
                 decrypt_status = decryptBook(userkey, inpath, outpath)
-            except Exception, e:
+            except Exception as e:
                 self.status['text'] = u"Error: {0}".format(e.args[0])
                 return
             if decrypt_status == 0:
diff --git a/DeDRM_plugin/ignoblekey.py b/DeDRM_plugin/ignoblekey.py
index fb7c6a8..0b3e60f 100644
--- a/DeDRM_plugin/ignoblekey.py
+++ b/DeDRM_plugin/ignoblekey.py
@@ -2,9 +2,10 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
 # ignoblekey.py
-# Copyright © 2015 Apprentice Alf and Apprentice Harper
+# Copyright © 2015-2020 Apprentice Alf, Apprentice Harper et al.
 
 # Based on kindlekey.py, Copyright © 2010-2013 by some_updates and Apprentice Alf
 
@@ -14,11 +15,11 @@ from __future__ import with_statement
 # Revision history:
 #   1.0 - Initial release
 #   1.1 - remove duplicates and return last key as single key
+#   2.0 - Added Python 3 compatibility for calibre 5.0
 
 """
 Get Barnes & Noble EPUB user key from nook Studio log file
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
 __version__ = "1.1"
@@ -39,7 +40,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -80,7 +81,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"ignoblekey.py"]
@@ -88,7 +89,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 class DrmException(Exception):
     pass
@@ -210,7 +211,7 @@ def getkey(outpath, files=[]):
     if len(keys) > 0:
         if not os.path.isdir(outpath):
             outfile = outpath
-            with file(outfile, 'w') as keyfileout:
+            with open(outfile, 'w') as keyfileout:
                 keyfileout.write(keys[-1])
             print(u"Saved a key to {0}".format(outfile))
         else:
@@ -221,7 +222,7 @@ def getkey(outpath, files=[]):
                     outfile = os.path.join(outpath,u"nookkey{0:d}.b64".format(keycount))
                     if not os.path.exists(outfile):
                         break
-                with file(outfile, 'w') as keyfileout:
+                with open(outfile, 'w') as keyfileout:
                     keyfileout.write(key)
                 print(u"Saved a key to {0}".format(outfile))
         return True
@@ -244,7 +245,7 @@ def cli_main():
 
     try:
         opts, args = getopt.getopt(argv[1:], "hk:")
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
         print(u"Error in options or arguments: {0}".format(err.args[0]))
         usage(progname)
         sys.exit(2)
@@ -315,11 +316,11 @@ def gui_main():
                 if not os.path.exists(outfile):
                     break
 
-            with file(outfile, 'w') as keyfileout:
+            with open(outfile, 'w') as keyfileout:
                 keyfileout.write(key)
             success = True
             tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
-    except DrmException, e:
+    except DrmException as e:
         tkMessageBox.showerror(progname, u"Error: {0}".format(str(e)))
     except Exception:
         root.wm_state('normal')
diff --git a/DeDRM_plugin/ignoblekeyfetch.py b/DeDRM_plugin/ignoblekeyfetch.py
index dd714fc..ffaf153 100644
--- a/DeDRM_plugin/ignoblekeyfetch.py
+++ b/DeDRM_plugin/ignoblekeyfetch.py
@@ -2,9 +2,10 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
-# ignoblekeyfetch.pyw, version 1.1
-# Copyright © 2015 Apprentice Harper
+# ignoblekeyfetch.pyw, version 2.0
+# Copyright © 2015-2020 Apprentice Harper et al.
 
 # Released under the terms of the GNU General Public Licence, version 3
 # <http://www.gnu.org/licenses/>
@@ -24,11 +25,11 @@ from __future__ import with_statement
 # Revision history:
 #   1.0 - Initial  version
 #   1.1 - Try second URL if first one fails
+#   2.0 - Added Python 3 compatibility for calibre 5.0
 
 """
 Fetch Barnes & Noble EPUB user key from B&N servers using email and password
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
 __version__ = "1.1"
@@ -46,7 +47,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -87,7 +88,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"ignoblekeyfetch.py"]
@@ -95,7 +96,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 
 class IGNOBLEError(Exception):
@@ -103,9 +104,9 @@ class IGNOBLEError(Exception):
 
 def fetch_key(email, password):
     # change email and password to utf-8 if unicode
-    if type(email)==unicode:
+    if type(email)==bytes:
         email = email.encode('utf-8')
-    if type(password)==unicode:
+    if type(password)==bytes:
         password = password.encode('utf-8')
 
     import random
@@ -236,7 +237,7 @@ def gui_main():
             self.status['text'] = u"Fetching..."
             try:
                 userkey = fetch_key(email, password)
-            except Exception, e:
+            except Exception as e:
                 self.status['text'] = u"Error: {0}".format(e.args[0])
                 return
             if len(userkey) == 28:
diff --git a/DeDRM_plugin/ignoblekeygen.py b/DeDRM_plugin/ignoblekeygen.py
index 5ddcd80..3582f24 100644
--- a/DeDRM_plugin/ignoblekeygen.py
+++ b/DeDRM_plugin/ignoblekeygen.py
@@ -2,15 +2,14 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
+from __future__ import print_function
 
-# ignoblekeygen.pyw, version 2.5
-# Copyright © 2009-2010 i♥cabbages
+# ignoblekeygen.pyw
+# Copyright © 2009-2020 i♥cabbages, Apprentice Harper et al.
 
 # Released under the terms of the GNU General Public Licence, version 3
 # <http://www.gnu.org/licenses/>
 
-# Modified 2010–2013 by some_updates, DiapDealer and Apprentice Alf
-
 # Windows users: Before running this program, you must first install Python.
 #   We recommend ActiveState Python 2.7.X for Windows (x86) from
 #   http://www.activestate.com/activepython/downloads.
@@ -34,14 +33,14 @@ from __future__ import with_statement
 #   2.6 - moved unicode_argv call inside main for Windows DeDRM compatibility
 #   2.7 - Work if TkInter is missing
 #   2.8 - Fix bug in stand-alone use (import tkFileDialog)
+#   3.0 - Added Python 3 compatibility for calibre 5.0
 
 """
 Generate Barnes & Noble EPUB user key from name and credit card number.
 """
-from __future__ import print_function
 
 __license__ = 'GPL v3'
-__version__ = "2.8"
+__version__ = "3.0"
 
 import sys
 import os
@@ -57,7 +56,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -98,7 +97,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"ignoblekeygen.py"]
@@ -106,7 +105,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 
 class IGNOBLEError(Exception):
@@ -199,9 +198,9 @@ def normalize_name(name):
 
 def generate_key(name, ccn):
     # remove spaces and case from name and CC numbers.
-    if type(name)==unicode:
+    if type(name)==bytes:
         name = name.encode('utf-8')
-    if type(ccn)==unicode:
+    if type(ccn)==bytes:
         ccn = ccn.encode('utf-8')
 
     name = normalize_name(name) + '\x00'
@@ -306,7 +305,7 @@ def gui_main():
             self.status['text'] = u"Generating..."
             try:
                 userkey = generate_key(name, ccn)
-            except Exception, e:
+            except Exception as e:
                 self.status['text'] = u"Error: (0}".format(e.args[0])
                 return
             open(keypath,'wb').write(userkey)
diff --git a/DeDRM_plugin/ineptepub.py b/DeDRM_plugin/ineptepub.py
index cfbd084..c0e4c39 100644
--- a/DeDRM_plugin/ineptepub.py
+++ b/DeDRM_plugin/ineptepub.py
@@ -2,18 +2,13 @@
 # -*- coding: utf-8 -*-
 
 from __future__ import with_statement
-from __future__ import absolute_import
-from __future__ import print_function
 
-# ineptepub.pyw, version 6.6
-# Copyright © 2009-2020 by Apprentice Harper et al.
+# ineptepub.pyw
+# Copyright © 2009-2020 by i♥cabbages, Apprentice Harper et al.
 
 # Released under the terms of the GNU General Public Licence, version 3
 # <http://www.gnu.org/licenses/>
 
-# Original script by i♥cabbages
-# Modified 2010–2013 by some_updates, DiapDealer and Apprentice Alf
-# Modified 2015–2020 by Apprentice Harper et al.
 
 # Revision history:
 #   1 - Initial release
@@ -36,17 +31,16 @@ from __future__ import print_function
 #   6.4 - Remove erroneous check on DER file sanity
 #   6.5 - Completely remove erroneous check on DER file sanity
 #   6.6 - Import tkFileDialog, don't assume something else will import it.
-#   6.7 - Add Python 3 compatibility while still working with Python 2.7
+#   7.0 - Add Python 3 compatibility for calibre 5.0
 
 """
 Decrypt Adobe Digital Editions encrypted ePub books.
 """
 
 __license__ = 'GPL v3'
-__version__ = "6.7"
+__version__ = "7.0"
 
-import six
-from six.moves import range
+import codecs
 import sys
 import os
 import traceback
@@ -55,7 +49,6 @@ import zipfile
 from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
 from contextlib import closing
 import xml.etree.ElementTree as etree
-import base64
 
 # Wrap a stream so that output gets flushed immediately
 # and also make sure that any unicode strings get
@@ -67,7 +60,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,six.text_type):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -114,7 +107,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == six.text_type) else six.text_type(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 
 class ADEPTError(Exception):
@@ -418,9 +411,7 @@ def decryptBook(userkey, inpath, outpath):
             if len(bookkey) != 172:
                 print(u"{0:s} is not a secure Adobe Adept ePub.".format(os.path.basename(inpath)))
                 return 1
-            bookkey = bookkey.encode('ascii')
-            bookkey = base64.b64decode(bookkey)
-            bookkey = rsa.decrypt(bookkey)
+            bookkey = rsa.decrypt(codecs.decode(bookkey.encode('ascii'), 'base64'))
             # Padded as per RSAES-PKCS1-v1_5
             if bookkey[-17] != '\x00' and bookkey[-17] != 0:
                 print(u"Could not decrypt {0:s}. Wrong key".format(os.path.basename(inpath)))
@@ -486,79 +477,79 @@ def cli_main():
 
 def gui_main():
     try:
-        import six.moves.tkinter
-        import six.moves.tkinter_constants
-        import six.moves.tkinter_filedialog
-        import six.moves.tkinter_messagebox
+        import Tkinter
+        import Tkconstants
+        import tkFileDialog
+        import tkMessageBox
         import traceback
     except:
         return cli_main()
 
-    class DecryptionDialog(six.moves.tkinter.Frame):
+    class DecryptionDialog(Tkinter.Frame):
         def __init__(self, root):
-            six.moves.tkinter.Frame.__init__(self, root, border=5)
-            self.status = six.moves.tkinter.Label(self, text=u"Select files for decryption")
-            self.status.pack(fill=six.moves.tkinter_constants.X, expand=1)
-            body = six.moves.tkinter.Frame(self)
-            body.pack(fill=six.moves.tkinter_constants.X, expand=1)
-            sticky = six.moves.tkinter_constants.E + six.moves.tkinter_constants.W
+            Tkinter.Frame.__init__(self, root, border=5)
+            self.status = Tkinter.Label(self, text=u"Select files for decryption")
+            self.status.pack(fill=Tkconstants.X, expand=1)
+            body = Tkinter.Frame(self)
+            body.pack(fill=Tkconstants.X, expand=1)
+            sticky = Tkconstants.E + Tkconstants.W
             body.grid_columnconfigure(1, weight=2)
-            six.moves.tkinter.Label(body, text=u"Key file").grid(row=0)
-            self.keypath = six.moves.tkinter.Entry(body, width=30)
+            Tkinter.Label(body, text=u"Key file").grid(row=0)
+            self.keypath = Tkinter.Entry(body, width=30)
             self.keypath.grid(row=0, column=1, sticky=sticky)
             if os.path.exists(u"adeptkey.der"):
                 self.keypath.insert(0, u"adeptkey.der")
-            button = six.moves.tkinter.Button(body, text=u"...", command=self.get_keypath)
+            button = Tkinter.Button(body, text=u"...", command=self.get_keypath)
             button.grid(row=0, column=2)
-            six.moves.tkinter.Label(body, text=u"Input file").grid(row=1)
-            self.inpath = six.moves.tkinter.Entry(body, width=30)
+            Tkinter.Label(body, text=u"Input file").grid(row=1)
+            self.inpath = Tkinter.Entry(body, width=30)
             self.inpath.grid(row=1, column=1, sticky=sticky)
-            button = six.moves.tkinter.Button(body, text=u"...", command=self.get_inpath)
+            button = Tkinter.Button(body, text=u"...", command=self.get_inpath)
             button.grid(row=1, column=2)
-            six.moves.tkinter.Label(body, text=u"Output file").grid(row=2)
-            self.outpath = six.moves.tkinter.Entry(body, width=30)
+            Tkinter.Label(body, text=u"Output file").grid(row=2)
+            self.outpath = Tkinter.Entry(body, width=30)
             self.outpath.grid(row=2, column=1, sticky=sticky)
-            button = six.moves.tkinter.Button(body, text=u"...", command=self.get_outpath)
+            button = Tkinter.Button(body, text=u"...", command=self.get_outpath)
             button.grid(row=2, column=2)
-            buttons = six.moves.tkinter.Frame(self)
+            buttons = Tkinter.Frame(self)
             buttons.pack()
-            botton = six.moves.tkinter.Button(
+            botton = Tkinter.Button(
                 buttons, text=u"Decrypt", width=10, command=self.decrypt)
-            botton.pack(side=six.moves.tkinter_constants.LEFT)
-            six.moves.tkinter.Frame(buttons, width=10).pack(side=six.moves.tkinter_constants.LEFT)
-            button = six.moves.tkinter.Button(
+            botton.pack(side=Tkconstants.LEFT)
+            Tkinter.Frame(buttons, width=10).pack(side=Tkconstants.LEFT)
+            button = Tkinter.Button(
                 buttons, text=u"Quit", width=10, command=self.quit)
-            button.pack(side=six.moves.tkinter_constants.RIGHT)
+            button.pack(side=Tkconstants.RIGHT)
 
         def get_keypath(self):
-            keypath = six.moves.tkinter_filedialog.askopenfilename(
+            keypath = tkFileDialog.askopenfilename(
                 parent=None, title=u"Select Adobe Adept \'.der\' key file",
                 defaultextension=u".der",
                 filetypes=[('Adobe Adept DER-encoded files', '.der'),
                            ('All Files', '.*')])
             if keypath:
                 keypath = os.path.normpath(keypath)
-                self.keypath.delete(0, six.moves.tkinter_constants.END)
+                self.keypath.delete(0, Tkconstants.END)
                 self.keypath.insert(0, keypath)
             return
 
         def get_inpath(self):
-            inpath = six.moves.tkinter_filedialog.askopenfilename(
+            inpath = tkFileDialog.askopenfilename(
                 parent=None, title=u"Select ADEPT-encrypted ePub file to decrypt",
                 defaultextension=u".epub", filetypes=[('ePub files', '.epub')])
             if inpath:
                 inpath = os.path.normpath(inpath)
-                self.inpath.delete(0, six.moves.tkinter_constants.END)
+                self.inpath.delete(0, Tkconstants.END)
                 self.inpath.insert(0, inpath)
             return
 
         def get_outpath(self):
-            outpath = six.moves.tkinter_filedialog.asksaveasfilename(
+            outpath = tkFileDialog.asksaveasfilename(
                 parent=None, title=u"Select unencrypted ePub file to produce",
                 defaultextension=u".epub", filetypes=[('ePub files', '.epub')])
             if outpath:
                 outpath = os.path.normpath(outpath)
-                self.outpath.delete(0, six.moves.tkinter_constants.END)
+                self.outpath.delete(0, Tkconstants.END)
                 self.outpath.insert(0, outpath)
             return
 
@@ -590,11 +581,11 @@ def gui_main():
             else:
                 self.status['text'] = u"The was an error decrypting the file."
 
-    root = six.moves.tkinter.Tk()
+    root = Tkinter.Tk()
     root.title(u"Adobe Adept ePub Decrypter v.{0}".format(__version__))
     root.resizable(True, False)
     root.minsize(300, 0)
-    DecryptionDialog(root).pack(fill=six.moves.tkinter_constants.X, expand=1)
+    DecryptionDialog(root).pack(fill=Tkconstants.X, expand=1)
     root.mainloop()
     return 0
 
diff --git a/DeDRM_plugin/ineptpdf.py b/DeDRM_plugin/ineptpdf.py
index 17db7e9..c29a536 100644
--- a/DeDRM_plugin/ineptpdf.py
+++ b/DeDRM_plugin/ineptpdf.py
@@ -4,13 +4,11 @@
 from __future__ import with_statement
 
 # ineptpdf.py
-# Copyright © 2009-2017 by Apprentice Harper et al.
+# Copyright © 2009-2020 by i♥cabbages, Apprentice Harper et al.
 
 # Released under the terms of the GNU General Public Licence, version 3
 # <http://www.gnu.org/licenses/>
 
-# Modified 2010–2012 by some_updates, DiapDealer and Apprentice Alf
-# Modified 2015-2017 by Apprentice Harper et al.
 
 # Revision history:
 #   1 - Initial release
@@ -49,14 +47,14 @@ from __future__ import with_statement
 #   8.0.4 - Completely remove erroneous check on DER file sanity
 #   8.0.5 - Do not process DRM-free documents
 #   8.0.6 - Replace use of float by Decimal for greater precision, and import tkFileDialog
-
+#   9.0.0 - Add Python 3 compatibility for calibre 5
 
 """
 Decrypts Adobe ADEPT-encrypted PDF files.
 """
 
 __license__ = 'GPL v3'
-__version__ = "8.0.6"
+__version__ = "9.0.0"
 
 import sys
 import os
@@ -64,8 +62,8 @@ import re
 import zlib
 import struct
 import hashlib
-from decimal import *
-from itertools import chain, islice
+from decimal import Decimal
+import itertools
 import xml.etree.ElementTree as etree
 
 # Wrap a stream so that output gets flushed immediately
@@ -75,10 +73,10 @@ class SafeUnbuffered:
     def __init__(self, stream):
         self.stream = stream
         self.encoding = stream.encoding
-        if self.encoding == None:
+        if self.encoding is None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -116,13 +114,13 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         return [u"ineptpdf.py"]
     else:
         argvencoding = sys.stdin.encoding
-        if argvencoding == None:
+        if argvencoding is None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return sys.argv
 
 
 class ADEPTError(Exception):
@@ -378,12 +376,12 @@ def _load_crypto_pycrypto():
     class RSA(object):
         def __init__(self, der):
             key = ASN1Parser([ord(x) for x in der])
-            key = [key.getChild(x).value for x in xrange(1, 4)]
+            key = [key.getChild(x).value for x in range(1, 4)]
             key = [self.bytesToNumber(v) for v in key]
             self._rsa = _RSA.construct(key)
 
         def bytesToNumber(self, bytes):
-            total = 0L
+            total = 0
             for byte in bytes:
                 total = (total << 8) + byte
             return total
@@ -411,7 +409,10 @@ ARC4, RSA, AES = _load_crypto()
 try:
     from cStringIO import StringIO
 except ImportError:
-    from StringIO import StringIO
+    try:
+        from StringIO import StringIO
+    except ImportError:
+        from io import StringIO
 
 
 # Do we generate cross reference streams on output?
@@ -444,11 +445,11 @@ def nunpack(s, default=0):
     if not l:
         return default
     elif l == 1:
-        return ord(s)
+        return s
     elif l == 2:
         return struct.unpack('>H', s)[0]
     elif l == 3:
-        return struct.unpack('>L', '\x00'+s)[0]
+        return struct.unpack('>L', b'\x00'+s)[0]
     elif l == 4:
         return struct.unpack('>L', s)[0]
     else:
@@ -487,9 +488,9 @@ class PSLiteral(PSObject):
         name = []
         for char in self.name:
             if not char.isalnum():
-                char = '#%02x' % ord(char)
+                char = b'#%02x' % char
             name.append(char)
-        return '/%s' % ''.join(name)
+        return b'/%s' % ''.join(name)
 
 # PSKeyword
 class PSKeyword(PSObject):
@@ -716,7 +717,7 @@ class PSBaseParser(object):
         except ValueError:
             pass
         return (self.parse_main, j)
-        
+
     def parse_decimal(self, s, i):
         m = END_NUMBER.search(s, i)
         if not m:
@@ -949,7 +950,7 @@ class PSStackParser(PSBaseParser):
                 try:
                     (pos, objs) = self.end_type('d')
                     if len(objs) % 2 != 0:
-                        print "Incomplete dictionary construct"
+                        print("Incomplete dictionary construct")
                         objs.append("") # this isn't necessary.
                         # temporary fix. is this due to rental books?
                         # raise PSSyntaxError(
@@ -1106,18 +1107,18 @@ def stream_value(x):
 # ascii85decode(data)
 def ascii85decode(data):
     n = b = 0
-    out = ''
+    out = b''
     for c in data:
-        if '!' <= c and c <= 'u':
+        if b'!' <= c and c <= b'u':
             n += 1
-            b = b*85+(ord(c)-33)
+            b = b*85+(c-33)
             if n == 5:
                 out += struct.pack('>L',b)
                 n = b = 0
-        elif c == 'z':
+        elif c == b'z':
             assert n == 0
-            out += '\0\0\0\0'
-        elif c == '~':
+            out += b'\0\0\0\0'
+        elif c == b'~':
             if n:
                 for _ in range(5-n):
                     b = b*85+84
@@ -1138,7 +1139,7 @@ class PDFStream(PDFObject):
                 cutdiv = len(rawdata) // 16
                 rawdata = rawdata[:16*cutdiv]
         else:
-            if eol in ('\r', '\n', '\r\n'):
+            if eol in (b'\r', b'\n', b'\r\n'):
                 rawdata = rawdata[:length]
 
         self.dic = dic
@@ -1206,14 +1207,14 @@ class PDFStream(PDFObject):
                         raise PDFValueError(
                             'Columns undefined for predictor=12')
                     columns = int_value(params['Columns'])
-                    buf = ''
-                    ent0 = '\x00' * columns
-                    for i in xrange(0, len(data), columns+1):
+                    buf = b''
+                    ent0 = b'\x00' * columns
+                    for i in range(0, len(data), columns+1):
                         pred = data[i]
                         ent1 = data[i+1:i+1+columns]
-                        if pred == '\x02':
-                            ent1 = ''.join(chr((ord(a)+ord(b)) & 255) \
-                                               for (a,b) in zip(ent0,ent1))
+                        if pred == b'\x02':
+                            ent1 = ''.join(bytes([(a+b) & 255]) \
+                                           for (a,b) in zip(ent0,ent1))
                         buf += ent1
                         ent0 = ent1
                     data = buf
@@ -1290,7 +1291,7 @@ class PDFXRef(object):
                 (start, nobjs) = map(int, f)
             except ValueError:
                 raise PDFNoValidXRef('Invalid line: %r: line=%r' % (parser, line))
-            for objid in xrange(start, start+nobjs):
+            for objid in range(start, start+nobjs):
                 try:
                     (_, line) = parser.nextline()
                 except PSEOF:
@@ -1342,7 +1343,7 @@ class PDFXRefStream(object):
 
     def objids(self):
         for first, size in self.index:
-            for objid in xrange(first, first + size):
+            for objid in range(first, first + size):
                 yield objid
 
     def load(self, parser, debug=0):
@@ -1355,8 +1356,8 @@ class PDFXRefStream(object):
             raise PDFNoValidXRef('Invalid PDF stream spec.')
         size = stream.dic['Size']
         index = stream.dic.get('Index', (0,size))
-        self.index = zip(islice(index, 0, None, 2),
-                         islice(index, 1, None, 2))
+        self.index = zip(itertools.islice(index, 0, None, 2),
+                         itertools.islice(index, 1, None, 2))
         (self.fl1, self.fl2, self.fl3) = stream.dic['W']
         self.data = stream.get_data()
         self.entlen = self.fl1+self.fl2+self.fl3
@@ -1506,10 +1507,10 @@ class PDFDocument(object):
         if plaintext[-16:] != 16 * chr(16):
             raise ADEPTError('Offlinekey cannot be decrypted, aborting ...')
         pdrlpol = AES.new(plaintext[16:32],AES.MODE_CBC,edclist[2].decode('base64')).decrypt(pdrlpol)
-        if ord(pdrlpol[-1]) < 1 or ord(pdrlpol[-1]) > 16:
+        if pdrlpol[-1] < 1 or pdrlpol[-1] > 16:
             raise ADEPTError('Could not decrypt PDRLPol, aborting ...')
         else:
-            cutter = -1 * ord(pdrlpol[-1])
+            cutter = -1 * pdrlpol[-1]
             pdrlpol = pdrlpol[:cutter]
         return plaintext[:16]
 
@@ -1551,7 +1552,7 @@ class PDFDocument(object):
             hash.update('ffffffff'.decode('hex'))
         if 5 <= R:
             # 8
-            for _ in xrange(50):
+            for _ in range(50):
                 hash = hashlib.md5(hash.digest()[:length/8])
         key = hash.digest()[:length/8]
         if R == 2:
@@ -1562,8 +1563,8 @@ class PDFDocument(object):
             hash = hashlib.md5(self.PASSWORD_PADDING) # 2
             hash.update(docid[0]) # 3
             x = ARC4.new(key).decrypt(hash.digest()[:16]) # 4
-            for i in xrange(1,19+1):
-                k = ''.join( chr(ord(c) ^ i) for c in key )
+            for i in range(1,19+1):
+                k = ''.join(bytes([c ^ i]) for c in key )
                 x = ARC4.new(k).decrypt(x)
             u1 = x+x # 32bytes total
         if R == 2:
@@ -1585,9 +1586,9 @@ class PDFDocument(object):
         if V != 4:
             self.decipher = self.decipher_rc4  # XXX may be AES
         # aes
-        elif V == 4 and Length == 128:
-            elf.decipher = self.decipher_aes
-        elif V == 4 and Length == 256:
+        elif V == 4 and length == 128:
+            self.decipher = self.decipher_aes
+        elif V == 4 and length == 256:
             raise PDFNotImplementedError('AES256 encryption is currently unsupported')
         self.ready = True
         return
@@ -1616,18 +1617,18 @@ class PDFDocument(object):
                 else:
                     V = 2
             elif len(bookkey) == length + 1:
-                V = ord(bookkey[0])
+                V = bookkey[0]
                 bookkey = bookkey[1:]
             else:
-                print "ebx_V is %d  and ebx_type is %d" % (ebx_V, ebx_type)
-                print "length is %d and len(bookkey) is %d" % (length, len(bookkey))
-                print "bookkey[0] is %d" % ord(bookkey[0])
+                print("ebx_V is %d  and ebx_type is %d" % (ebx_V, ebx_type))
+                print("length is %d and len(bookkey) is %d" % (length, len(bookkey)))
+                print("bookkey[0] is %d" % bookkey[0])
                 raise ADEPTError('error decrypting book session key - mismatched length')
         else:
             # proper length unknown try with whatever you have
-            print "ebx_V is %d  and ebx_type is %d" % (ebx_V, ebx_type)
-            print "length is %d and len(bookkey) is %d" % (length, len(bookkey))
-            print "bookkey[0] is %d" % ord(bookkey[0])
+            print("ebx_V is %d  and ebx_type is %d" % (ebx_V, ebx_type))
+            print("length is %d and len(bookkey) is %d" % (length, len(bookkey)))
+            print("bookkey[0] is %d" % bookkey[0])
             if ebx_V == 3:
                 V = 3
             else:
@@ -1671,7 +1672,7 @@ class PDFDocument(object):
         data = data[16:]
         plaintext = AES.new(key,AES.MODE_CBC,ivector).decrypt(data)
         # remove pkcs#5 aes padding
-        cutter = -1 * ord(plaintext[-1])
+        cutter = -1 * plaintext[-1]
         #print cutter
         plaintext = plaintext[:cutter]
         return plaintext
@@ -1682,7 +1683,7 @@ class PDFDocument(object):
         data = data[16:]
         plaintext = AES.new(key,AES.MODE_CBC,ivector).decrypt(data)
         # remove pkcs#5 aes padding
-        cutter = -1 * ord(plaintext[-1])
+        cutter = -1 * plaintext[-1]
         #print cutter
         plaintext = plaintext[:cutter]
         return plaintext
@@ -2026,7 +2027,7 @@ class PDFSerializer(object):
         if not gen_xref_stm:
             self.write('xref\n')
             self.write('0 %d\n' % (maxobj + 1,))
-            for objid in xrange(0, maxobj + 1):
+            for objid in range(0, maxobj + 1):
                 if objid in xrefs:
                     # force the genno to be 0
                     self.write("%010d 00000 n \n" % xrefs[objid][0])
@@ -2135,7 +2136,7 @@ class PDFSerializer(object):
             if self.last.isalnum():
                 self.write(' ')
             self.write(str(obj).lower())
-        elif isinstance(obj, (int, long)):
+        elif isinstance(obj, int):
             if self.last.isalnum():
                 self.write(' ')
             self.write(str(obj))
@@ -2189,8 +2190,8 @@ def decryptBook(userkey, inpath, outpath):
             # help construct to make sure the method runs to the end
             try:
                 serializer.dump(outf)
-            except Exception, e:
-                print u"error writing pdf: {0}".format(e.args[0])
+            except Exception as e:
+                print(u"error writing pdf: {0}".format(e.args[0]))
                 return 2
     return 0
 
@@ -2201,13 +2202,13 @@ def cli_main():
     argv=unicode_argv()
     progname = os.path.basename(argv[0])
     if len(argv) != 4:
-        print u"usage: {0} <keyfile.der> <inbook.pdf> <outbook.pdf>".format(progname)
+        print(u"usage: {0} <keyfile.der> <inbook.pdf> <outbook.pdf>".format(progname))
         return 1
     keypath, inpath, outpath = argv[1:]
     userkey = open(keypath,'rb').read()
     result = decryptBook(userkey, inpath, outpath)
     if result == 0:
-        print u"Successfully decrypted {0:s} as {1:s}".format(os.path.basename(inpath),os.path.basename(outpath))
+        print(u"Successfully decrypted {0:s} as {1:s}".format(os.path.basename(inpath),os.path.basename(outpath)))
     return result
 
 
@@ -2309,7 +2310,7 @@ def gui_main():
             self.status['text'] = u"Decrypting..."
             try:
                 decrypt_status = decryptBook(userkey, inpath, outpath)
-            except Exception, e:
+            except Exception as e:
                 self.status['text'] = u"Error; {0}".format(e.args[0])
                 return
             if decrypt_status == 0:
diff --git a/DeDRM_plugin/ion.py b/DeDRM_plugin/ion.py
index 0ea3859..f385cc3 100644
--- a/DeDRM_plugin/ion.py
+++ b/DeDRM_plugin/ion.py
@@ -7,7 +7,7 @@ from __future__ import with_statement
 # Copyright © 2013-2020 Apprentice Harper et al.
 
 __license__ = 'GPL v3'
-__version__ = '2.0'
+__version__ = '3.0'
 
 # Revision history:
 #  Pascal implementation by lulzkabulz.
@@ -17,7 +17,7 @@ __version__ = '2.0'
 #  1.2   - Added pylzma import fallback
 #  1.3   - Fixed lzma support for calibre 4.6+
 #  2.0   - VoucherEnvelope v2/v3 support by apprenticesakuya.
-
+#  3.0   - Added Python 3 compatibility for calibre 5.0
 
 """
 Decrypt Kindle KFX files.
@@ -33,7 +33,10 @@ import struct
 try:
     from cStringIO import StringIO
 except ImportError:
-    from StringIO import StringIO
+    try:
+        from StringIO import StringIO
+    except ImportError:
+        from io import StringIO
 
 from Crypto.Cipher import AES
 from Crypto.Util.py3compat import bchr, bord
diff --git a/DeDRM_plugin/k4mobidedrm.py b/DeDRM_plugin/k4mobidedrm.py
index 3ac753e..eaaa43b 100644
--- a/DeDRM_plugin/k4mobidedrm.py
+++ b/DeDRM_plugin/k4mobidedrm.py
@@ -4,10 +4,10 @@
 from __future__ import with_statement
 
 # k4mobidedrm.py
-# Copyright © 2008-2019 by Apprentice Harper et al.
+# Copyright © 2008-2020 by Apprentice Harper et al.
 
 __license__ = 'GPL v3'
-__version__ = '5.7'
+__version__ = '6.0'
 
 # Engine to remove drm from Kindle and Mobipocket ebooks
 # for personal use for archiving and converting your ebooks
@@ -62,6 +62,8 @@ __version__ = '5.7'
 #  5.5 - Added GPL v3 licence explicitly.
 #  5.6 - Invoke KFXZipBook to handle zipped KFX files
 #  5.7 - Revamp cleanup_name
+#  6.0 - Added Python 3 compatibility for calibre 5.0
+
 
 import sys, os, re
 import csv
@@ -69,7 +71,7 @@ import getopt
 import re
 import traceback
 import time
-import htmlentitydefs
+import html.entities
 import json
 
 class DrmException(Exception):
@@ -103,7 +105,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -141,7 +143,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"mobidedrm.py"]
@@ -149,7 +151,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 # cleanup unicode filenames
 # borrowed from calibre from calibre/src/calibre/__init__.py
@@ -161,7 +163,7 @@ def cleanup_name(name):
     # substitute filename unfriendly characters
     name = name.replace(u"<",u"[").replace(u">",u"]").replace(u" : ",u" – ").replace(u": ",u" – ").replace(u":",u"—").replace(u"/",u"_").replace(u"\\",u"_").replace(u"|",u"_").replace(u"\"",u"\'").replace(u"*",u"_").replace(u"?",u"")
     # white space to single space, delete leading and trailing while space
-    name = re.sub(ur"\s", u" ", name).strip()
+    name = re.sub(r"\s", u" ", name).strip()
     # delete control characters
     name = u"".join(char for char in name if ord(char)>=32)
     # delete non-ascii characters
@@ -184,19 +186,19 @@ def unescape(text):
             # character reference
             try:
                 if text[:3] == u"&#x":
-                    return unichr(int(text[3:-1], 16))
+                    return chr(int(text[3:-1], 16))
                 else:
-                    return unichr(int(text[2:-1]))
+                    return chr(int(text[2:-1]))
             except ValueError:
                 pass
         else:
             # named entity
             try:
-                text = unichr(htmlentitydefs.name2codepoint[text[1:-1]])
+                text = chr(htmlentitydefs.name2codepoint[text[1:-1]])
             except KeyError:
                 pass
         return text # leave as is
-    return re.sub(u"&#?\w+;", fixup, text)
+    return re.sub(u"&#?\\w+;", fixup, text)
 
 def GetDecryptedBook(infile, kDatabases, androidFiles, serials, pids, starttime = time.time()):
     # handle the obvious cases at the beginning
@@ -220,7 +222,7 @@ def GetDecryptedBook(infile, kDatabases, androidFiles, serials, pids, starttime
         mb = topazextract.TopazBook(infile)
 
     bookname = unescape(mb.getBookTitle())
-    print u"Decrypting {1} ebook: {0}".format(bookname, mb.getBookType())
+    print(u"Decrypting {1} ebook: {0}".format(bookname, mb.getBookType()))
 
     # copy list of pids
     totalpids = list(pids)
@@ -232,7 +234,7 @@ def GetDecryptedBook(infile, kDatabases, androidFiles, serials, pids, starttime
     totalpids.extend(kgenpids.getPidList(md1, md2, serials, kDatabases))
     # remove any duplicates
     totalpids = list(set(totalpids))
-    print u"Found {1:d} keys to try after {0:.1f} seconds".format(time.time()-starttime, len(totalpids))
+    print(u"Found {1:d} keys to try after {0:.1f} seconds".format(time.time()-starttime, len(totalpids)))
     #print totalpids
 
     try:
@@ -241,7 +243,7 @@ def GetDecryptedBook(infile, kDatabases, androidFiles, serials, pids, starttime
         mb.cleanup
         raise
 
-    print u"Decryption succeeded after {0:.1f} seconds".format(time.time()-starttime)
+    print(u"Decryption succeeded after {0:.1f} seconds".format(time.time()-starttime))
     return mb
 
 
@@ -255,16 +257,16 @@ def decryptBook(infile, outdir, kDatabaseFiles, androidFiles, serials, pids):
             with open(dbfile, 'r') as keyfilein:
                 kindleDatabase = json.loads(keyfilein.read())
             kDatabases.append([dbfile,kindleDatabase])
-        except Exception, e:
-            print u"Error getting database from file {0:s}: {1:s}".format(dbfile,e)
+        except Exception as e:
+            print(u"Error getting database from file {0:s}: {1:s}".format(dbfile,e))
             traceback.print_exc()
 
 
 
     try:
         book = GetDecryptedBook(infile, kDatabases, androidFiles, serials, pids, starttime)
-    except Exception, e:
-        print u"Error decrypting book after {1:.1f} seconds: {0}".format(e.args[0],time.time()-starttime)
+    except Exception as e:
+        print(u"Error decrypting book after {1:.1f} seconds: {0}".format(e.args[0],time.time()-starttime))
         traceback.print_exc()
         return 1
 
@@ -287,12 +289,12 @@ def decryptBook(infile, outdir, kDatabaseFiles, androidFiles, serials, pids):
     outfile = os.path.join(outdir, outfilename + book.getBookExtension())
 
     book.getFile(outfile)
-    print u"Saved decrypted book {1:s} after {0:.1f} seconds".format(time.time()-starttime, outfilename)
+    print(u"Saved decrypted book {1:s} after {0:.1f} seconds".format(time.time()-starttime, outfilename))
 
     if book.getBookType()==u"Topaz":
         zipname = os.path.join(outdir, outfilename + u"_SVG.zip")
         book.getSVGZip(zipname)
-        print u"Saved SVG ZIP Archive for {1:s} after {0:.1f} seconds".format(time.time()-starttime, outfilename)
+        print(u"Saved SVG ZIP Archive for {1:s} after {0:.1f} seconds".format(time.time()-starttime, outfilename))
 
     # remove internal temporary directory of Topaz pieces
     book.cleanup()
@@ -300,9 +302,9 @@ def decryptBook(infile, outdir, kDatabaseFiles, androidFiles, serials, pids):
 
 
 def usage(progname):
-    print u"Removes DRM protection from Mobipocket, Amazon KF8, Amazon Print Replica and Amazon Topaz ebooks"
-    print u"Usage:"
-    print u"    {0} [-k <kindle.k4i>] [-p <comma separated PIDs>] [-s <comma separated Kindle serial numbers>] [ -a <AmazonSecureStorage.xml|backup.ab> ] <infile> <outdir>".format(progname)
+    print(u"Removes DRM protection from Mobipocket, Amazon KF8, Amazon Print Replica and Amazon Topaz ebooks")
+    print(u"Usage:")
+    print(u"    {0} [-k <kindle.k4i>] [-p <comma separated PIDs>] [-s <comma separated Kindle serial numbers>] [ -a <AmazonSecureStorage.xml|backup.ab> ] <infile> <outdir>".format(progname))
 
 #
 # Main
@@ -310,12 +312,12 @@ def usage(progname):
 def cli_main():
     argv=unicode_argv()
     progname = os.path.basename(argv[0])
-    print u"K4MobiDeDrm v{0}.\nCopyright © 2008-2017 Apprentice Harper et al.".format(__version__)
+    print(u"K4MobiDeDrm v{0}.\nCopyright © 2008-2017 Apprentice Harper et al.".format(__version__))
 
     try:
         opts, args = getopt.getopt(argv[1:], "k:p:s:a:")
-    except getopt.GetoptError, err:
-        print u"Error in options or arguments: {0}".format(err.args[0])
+    except getopt.GetoptError as err:
+        print(u"Error in options or arguments: {0}".format(err.args[0]))
         usage(progname)
         sys.exit(2)
     if len(args)<2:
diff --git a/DeDRM_plugin/kfxdedrm.py b/DeDRM_plugin/kfxdedrm.py
index 1520f79..d3c0f7e 100644
--- a/DeDRM_plugin/kfxdedrm.py
+++ b/DeDRM_plugin/kfxdedrm.py
@@ -6,6 +6,9 @@ from __future__ import print_function
 
 # Engine to remove drm from Kindle KFX ebooks
 
+#  2.0   - Added Python 3 compatibility for calibre 5.0
+
+
 import os
 import shutil
 import zipfile
@@ -13,7 +16,10 @@ import zipfile
 try:
     from cStringIO import StringIO
 except ImportError:
-    from StringIO import StringIO
+    try:
+        from StringIO import StringIO
+    except ImportError:
+        from io import StringIO
 
 try:
     from calibre_plugins.dedrm import ion
@@ -22,7 +28,7 @@ except ImportError:
 
 
 __license__ = 'GPL v3'
-__version__ = '1.0'
+__version__ = '2.0'
 
 
 class KFXZipBook:
diff --git a/DeDRM_plugin/kgenpids.py b/DeDRM_plugin/kgenpids.py
index 529d13d..a3efee0 100644
--- a/DeDRM_plugin/kgenpids.py
+++ b/DeDRM_plugin/kgenpids.py
@@ -5,15 +5,17 @@ from __future__ import with_statement
 from __future__ import print_function
 
 # kgenpids.py
-# Copyright © 2008-2017 Apprentice Harper et al.
+# Copyright © 2008-2020 Apprentice Harper et al.
 
 __license__ = 'GPL v3'
-__version__ = '2.1'
+__version__ = '3.0'
 
 # Revision history:
 #  2.0   - Fix for non-ascii Windows user names
 #  2.1   - Actual fix for non-ascii WIndows user names.
-#  x.x   - Return information needed for KFX decryption
+#  2.2   - Return information needed for KFX decryption
+#  3.0   - Added Python 3 compatibility for calibre 5.0
+
 
 import sys
 import os, csv
@@ -31,9 +33,9 @@ global charMap3
 global charMap4
 
 
-charMap1 = 'n5Pr6St7Uv8Wx9YzAb0Cd1Ef2Gh3Jk4M'
-charMap3 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
-charMap4 = 'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789'
+charMap1 = b'n5Pr6St7Uv8Wx9YzAb0Cd1Ef2Gh3Jk4M'
+charMap3 = b'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+charMap4 = b'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789'
 
 # crypto digestroutines
 import hashlib
@@ -84,7 +86,7 @@ def decode(data,map):
 def getTwoBitsFromBitField(bitField,offset):
     byteNumber = offset // 4
     bitPosition = 6 - 2*(offset % 4)
-    return ord(bitField[byteNumber]) >> bitPosition & 3
+    return bitField[byteNumber] >> bitPosition & 3
 
 # Returns the six bits at offset from a bit field
 def getSixBitsFromBitField(bitField,offset):
@@ -95,9 +97,9 @@ def getSixBitsFromBitField(bitField,offset):
 # 8 bits to six bits encoding from hash to generate PID string
 def encodePID(hash):
     global charMap3
-    PID = ''
+    PID = b''
     for position in range (0,8):
-        PID += charMap3[getSixBitsFromBitField(hash,position)]
+        PID += bytes([charMap3[getSixBitsFromBitField(hash,position)]])
     return PID
 
 # Encryption table used to generate the device PID
@@ -126,7 +128,7 @@ def generatePidSeed(table,dsn) :
 def generateDevicePID(table,dsn,nbRoll):
     global charMap4
     seed = generatePidSeed(table,dsn)
-    pidAscii = ''
+    pidAscii = b''
     pid = [(seed >>24) &0xFF,(seed >> 16) &0xff,(seed >> 8) &0xFF,(seed) & 0xFF,(seed>>24) & 0xFF,(seed >> 16) &0xff,(seed >> 8) &0xFF,(seed) & 0xFF]
     index = 0
     for counter in range (0,nbRoll):
@@ -134,7 +136,7 @@ def generateDevicePID(table,dsn,nbRoll):
         index = (index+1) %8
     for counter in range (0,8):
         index = ((((pid[counter] >>5) & 3) ^ pid[counter]) & 0x1f) + (pid[counter] >> 7)
-        pidAscii += charMap4[index]
+        pidAscii += bytes([charMap4[index]])
     return pidAscii
 
 def crc32(s):
@@ -150,7 +152,7 @@ def checksumPid(s):
     for i in (0,1):
         b = crc & 0xff
         pos = (b // l) ^ (b % l)
-        res += charMap4[pos%l]
+        res += bytes([charMap4[pos%l]])
         crc >>= 8
     return res
 
@@ -160,15 +162,15 @@ def pidFromSerial(s, l):
     global charMap4
     crc = crc32(s)
     arr1 = [0]*l
-    for i in xrange(len(s)):
-        arr1[i%l] ^= ord(s[i])
+    for i in range(len(s)):
+        arr1[i%l] ^= s[i]
     crc_bytes = [crc >> 24 & 0xff, crc >> 16 & 0xff, crc >> 8 & 0xff, crc & 0xff]
-    for i in xrange(l):
+    for i in range(l):
         arr1[i] ^= crc_bytes[i&3]
-    pid = ""
-    for i in xrange(l):
+    pid = b""
+    for i in range(l):
         b = arr1[i] & 0xff
-        pid+=charMap4[(b >> 7) + ((b >> 5 & 3) ^ (b & 0x1f))]
+        pid += bytes([charMap4[(b >> 7) + ((b >> 5 & 3) ^ (b & 0x1f))]])
     return pid
 
 
@@ -179,7 +181,7 @@ def getKindlePids(rec209, token, serialnum):
 
     pids=[]
 
-    if isinstance(serialnum,unicode):
+    if isinstance(serialnum,str):
         serialnum = serialnum.encode('utf-8')
 
     # Compute book PID
@@ -189,7 +191,7 @@ def getKindlePids(rec209, token, serialnum):
     pids.append(bookPID)
 
     # compute fixed pid for old pre 2.5 firmware update pid as well
-    kindlePID = pidFromSerial(serialnum, 7) + "*"
+    kindlePID = pidFromSerial(serialnum, 7) + b"*"
     kindlePID = checksumPid(kindlePID)
     pids.append(kindlePID)
 
@@ -206,7 +208,7 @@ def getK4Pids(rec209, token, kindleDatabase):
 
     try:
         # Get the kindle account token, if present
-        kindleAccountToken = (kindleDatabase[1])['kindle.account.tokens'].decode('hex')
+        kindleAccountToken = bytearray.fromhex((kindleDatabase[1])['kindle.account.tokens']).decode()
 
     except KeyError:
         kindleAccountToken=""
@@ -214,30 +216,30 @@ def getK4Pids(rec209, token, kindleDatabase):
 
     try:
         # Get the DSN token, if present
-        DSN = (kindleDatabase[1])['DSN'].decode('hex')
+        DSN = bytearray.fromhex((kindleDatabase[1])['DSN']).decode()
         print(u"Got DSN key from database {0}".format(kindleDatabase[0]))
     except KeyError:
         # See if we have the info to generate the DSN
         try:
             # Get the Mazama Random number
-            MazamaRandomNumber = (kindleDatabase[1])['MazamaRandomNumber'].decode('hex')
+            MazamaRandomNumber = bytearray.fromhex((kindleDatabase[1])['MazamaRandomNumber']).decode()
             #print u"Got MazamaRandomNumber from database {0}".format(kindleDatabase[0])
 
             try:
                 # Get the SerialNumber token, if present
-                IDString = (kindleDatabase[1])['SerialNumber'].decode('hex')
+                IDString = bytearray.fromhex((kindleDatabase[1])['SerialNumber']).decode()
                 print(u"Got SerialNumber from database {0}".format(kindleDatabase[0]))
             except KeyError:
                  # Get the IDString we added
-                IDString = (kindleDatabase[1])['IDString'].decode('hex')
+                IDString = bytearray.fromhex((kindleDatabase[1])['IDString']).decode()
 
             try:
                 # Get the UsernameHash token, if present
-                encodedUsername = (kindleDatabase[1])['UsernameHash'].decode('hex')
+                encodedUsername = bytearray.fromhex((kindleDatabase[1])['UsernameHash']).decode()
                 print(u"Got UsernameHash from database {0}".format(kindleDatabase[0]))
             except KeyError:
                 # Get the UserName we added
-                UserName = (kindleDatabase[1])['UserName'].decode('hex')
+                UserName = bytearray.fromhex((kindleDatabase[1])['UserName']).decode()
                 # encode it
                 encodedUsername = encodeHash(UserName,charMap1)
                 #print u"encodedUsername",encodedUsername.encode('hex')
@@ -267,19 +269,19 @@ def getK4Pids(rec209, token, kindleDatabase):
     # Compute book PIDs
 
     # book pid
-    pidHash = SHA1(DSN+kindleAccountToken+rec209+token)
+    pidHash = SHA1(DSN.encode()+kindleAccountToken.encode()+rec209+token)
     bookPID = encodePID(pidHash)
     bookPID = checksumPid(bookPID)
     pids.append(bookPID)
 
     # variant 1
-    pidHash = SHA1(kindleAccountToken+rec209+token)
+    pidHash = SHA1(kindleAccountToken.encode()+rec209+token)
     bookPID = encodePID(pidHash)
     bookPID = checksumPid(bookPID)
     pids.append(bookPID)
 
     # variant 2
-    pidHash = SHA1(DSN+rec209+token)
+    pidHash = SHA1(DSN.encode()+rec209+token)
     bookPID = encodePID(pidHash)
     bookPID = checksumPid(bookPID)
     pids.append(bookPID)
@@ -297,14 +299,14 @@ def getPidList(md1, md2, serials=[], kDatabases=[]):
     for kDatabase in kDatabases:
         try:
             pidlst.extend(getK4Pids(md1, md2, kDatabase))
-        except Exception, e:
+        except Exception as e:
             print(u"Error getting PIDs from database {0}: {1}".format(kDatabase[0],e.args[0]))
             traceback.print_exc()
 
     for serialnum in serials:
         try:
             pidlst.extend(getKindlePids(md1, md2, serialnum))
-        except Exception, e:
+        except Exception as e:
             print(u"Error getting PIDs from serial number {0}: {1}".format(serialnum ,e.args[0]))
             traceback.print_exc()
 
diff --git a/DeDRM_plugin/kindlekey.py b/DeDRM_plugin/kindlekey.py
index 90862cb..5e9f5c8 100644
--- a/DeDRM_plugin/kindlekey.py
+++ b/DeDRM_plugin/kindlekey.py
@@ -7,7 +7,7 @@ from __future__ import with_statement
 # Copyright © 2008-2020 Apprentice Harper et al.
 
 __license__ = 'GPL v3'
-__version__ = '2.7'
+__version__ = '3.0'
 
 # Revision history:
 #  1.0   - Kindle info file decryption, extracted from k4mobidedrm, etc.
@@ -30,6 +30,7 @@ __version__ = '2.7'
 #  2.5   - Final Fix for Windows user names with non-ascii characters, thanks to oneofusoneofus
 #  2.6   - Start adding support for Kindle 1.25+ .kinf2018 file
 #  2.7   - Finish .kinf2018 support, PC & Mac by Apprentice Sakuya
+#  3.0   - Added Python 3 compatibility for calibre 5.0
 
 
 """
@@ -37,7 +38,7 @@ Retrieve Kindle for PC/Mac user key.
 """
 
 import sys, os, re
-from struct import pack, unpack
+from struct import pack, unpack, unpack_from
 import json
 import getopt
 
@@ -108,7 +109,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return arg
 
 class DrmException(Exception):
     pass
@@ -299,7 +300,7 @@ if iswindows:
                 numBlocks, numExtraBytes = divmod(len(self.bytesToDecrypt), self.blockSize)
                 if more == None:  # no more calls to decrypt, should have all the data
                     if numExtraBytes  != 0:
-                        raise DecryptNotBlockAlignedError, 'Data not block aligned on decrypt'
+                        raise DecryptNotBlockAlignedError('Data not block aligned on decrypt')
 
                 # hold back some bytes in case last decrypt has zero len
                 if (more != None) and (numExtraBytes == 0) and (numBlocks >0) :
@@ -341,7 +342,7 @@ if iswindows:
             def removePad(self, paddedBinaryString, blockSize):
                 """ Remove padding from a binary string """
                 if not(0<len(paddedBinaryString)):
-                    raise DecryptNotBlockAlignedError, 'Expected More Data'
+                    raise DecryptNotBlockAlignedError('Expected More Data')
                 return paddedBinaryString[:-ord(paddedBinaryString[-1])]
 
         class noPadding(Pad):
@@ -649,7 +650,7 @@ if iswindows:
             def __init__(self, key = None, padding = padWithPadLen(), keySize=16):
                 """ Initialize AES, keySize is in bytes """
                 if  not (keySize == 16 or keySize == 24 or keySize == 32) :
-                    raise BadKeySizeError, 'Illegal AES key size, must be 16, 24, or 32 bytes'
+                    raise BadKeySizeError('Illegal AES key size, must be 16, 24, or 32 bytes')
 
                 Rijndael.__init__( self, key, padding=padding, keySize=keySize, blockSize=16 )
 
@@ -935,7 +936,6 @@ if iswindows:
     # Returns Environmental Variables that contain unicode
     def getEnvironmentVariable(name):
         import ctypes
-        name = unicode(name) # make sure string argument is unicode
         n = ctypes.windll.kernel32.GetEnvironmentVariableW(name, None, 0)
         if n == 0:
             return None
@@ -1166,9 +1166,9 @@ if iswindows:
             # store values used in decryption
             DB['IDString'] = GetIDString()
             DB['UserName'] = GetUserName()
-            print u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(GetIDString(), GetUserName().encode('hex'))
+            print(u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(GetIDString(), GetUserName().encode('hex')))
         else:
-            print u"Couldn't decrypt file."
+            print(u"Couldn't decrypt file.")
             DB = {}
         return DB
 elif isosx:
@@ -1649,11 +1649,11 @@ elif isosx:
                 pass
         if len(DB)>6:
             # store values used in decryption
-            print u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(IDString, GetUserName())
+            print(u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(IDString, GetUserName()))
             DB['IDString'] = IDString
             DB['UserName'] = GetUserName()
         else:
-            print u"Couldn't decrypt file."
+            print(u"Couldn't decrypt file.")
             DB = {}
         return DB
 else:
@@ -1683,7 +1683,7 @@ def getkey(outpath, files=[]):
             outfile = outpath
             with file(outfile, 'w') as keyfileout:
                 keyfileout.write(json.dumps(keys[0]))
-            print u"Saved a key to {0}".format(outfile)
+            print(u"Saved a key to {0}".format(outfile))
         else:
             keycount = 0
             for key in keys:
@@ -1694,16 +1694,16 @@ def getkey(outpath, files=[]):
                         break
                 with file(outfile, 'w') as keyfileout:
                     keyfileout.write(json.dumps(key))
-                print u"Saved a key to {0}".format(outfile)
+                print(u"Saved a key to {0}".format(outfile))
         return True
     return False
 
 def usage(progname):
-    print u"Finds, decrypts and saves the default Kindle For Mac/PC encryption keys."
-    print u"Keys are saved to the current directory, or a specified output directory."
-    print u"If a file name is passed instead of a directory, only the first key is saved, in that file."
-    print u"Usage:"
-    print u"    {0:s} [-h] [-k <kindle.info>] [<outpath>]".format(progname)
+    print(u"Finds, decrypts and saves the default Kindle For Mac/PC encryption keys.")
+    print(u"Keys are saved to the current directory, or a specified output directory.")
+    print(u"If a file name is passed instead of a directory, only the first key is saved, in that file.")
+    print(u"Usage:")
+    print(u"    {0:s} [-h] [-k <kindle.info>] [<outpath>]".format(progname))
 
 
 def cli_main():
@@ -1711,12 +1711,12 @@ def cli_main():
     sys.stderr=SafeUnbuffered(sys.stderr)
     argv=unicode_argv()
     progname = os.path.basename(argv[0])
-    print u"{0} v{1}\nCopyright © 2010-2016 by some_updates, Apprentice Alf and Apprentice Harper".format(progname,__version__)
+    print(u"{0} v{1}\nCopyright © 2010-2016 by some_updates, Apprentice Alf and Apprentice Harper".format(progname,__version__))
 
     try:
         opts, args = getopt.getopt(argv[1:], "hk:")
-    except getopt.GetoptError, err:
-        print u"Error in options or arguments: {0}".format(err.args[0])
+    except getopt.GetoptError as err:
+        print(u"Error in options or arguments: {0}".format(err.args[0]))
         usage(progname)
         sys.exit(2)
 
@@ -1745,7 +1745,7 @@ def cli_main():
     outpath = os.path.realpath(os.path.normpath(outpath))
 
     if not getkey(outpath, files):
-        print u"Could not retrieve Kindle for Mac/PC key."
+        print(u"Could not retrieve Kindle for Mac/PC key.")
     return 0
 
 
@@ -1789,7 +1789,7 @@ def gui_main():
                 keyfileout.write(json.dumps(key))
             success = True
             tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
-    except DrmException, e:
+    except DrmException as e:
         tkMessageBox.showerror(progname, u"Error: {0}".format(str(e)))
     except Exception:
         root.wm_state('normal')
diff --git a/DeDRM_plugin/kindlepid.py b/DeDRM_plugin/kindlepid.py
index 726554f..069fdc0 100644
--- a/DeDRM_plugin/kindlepid.py
+++ b/DeDRM_plugin/kindlepid.py
@@ -10,6 +10,7 @@
 #  0.3 updated for unicode
 #  0.4 Added support for serial numbers starting with '9', fixed unicode bugs.
 #  0.5 moved unicode_argv call inside main for Windows DeDRM compatibility
+#  1.0 Added Python 3 compatibility for calibre 5.0
 
 from __future__ import print_function
 import sys
@@ -25,7 +26,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -63,7 +64,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"kindlepid.py"]
@@ -71,11 +72,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = "utf-8"
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
-
-if sys.hexversion >= 0x3000000:
-    print('This script is incompatible with Python 3.x. Please install Python 2.7.x.')
-    sys.exit(2)
+        return sys.argv
 
 letters = 'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789'
 
@@ -83,7 +80,7 @@ def crc32(s):
     return (~binascii.crc32(s,-1))&0xFFFFFFFF
 
 def checksumPid(s):
-    crc = crc32(s)
+    crc = crc32(s.encode('ascii'))
     crc = crc ^ (crc >> 16)
     res = s
     l = len(letters)
@@ -99,15 +96,15 @@ def pidFromSerial(s, l):
     crc = crc32(s)
 
     arr1 = [0]*l
-    for i in xrange(len(s)):
-        arr1[i%l] ^= ord(s[i])
+    for i in range(len(s)):
+        arr1[i%l] ^= s[i]
 
     crc_bytes = [crc >> 24 & 0xff, crc >> 16 & 0xff, crc >> 8 & 0xff, crc & 0xff]
-    for i in xrange(l):
+    for i in range(l):
         arr1[i] ^= crc_bytes[i&3]
 
     pid = ''
-    for i in xrange(l):
+    for i in range(l):
         b = arr1[i] & 0xff
         pid+=letters[(b >> 7) + ((b >> 5 & 3) ^ (b & 0x1f))]
 
@@ -140,6 +137,6 @@ def cli_main():
 
 
 if __name__ == "__main__":
-    sys.stdout=SafeUnbuffered(sys.stdout)
-    sys.stderr=SafeUnbuffered(sys.stderr)
+    #sys.stdout=SafeUnbuffered(sys.stdout)
+    #sys.stderr=SafeUnbuffered(sys.stderr)
     sys.exit(cli_main())
diff --git a/DeDRM_plugin/mobidedrm.py b/DeDRM_plugin/mobidedrm.py
index e8400e4..cfd8a81 100644
--- a/DeDRM_plugin/mobidedrm.py
+++ b/DeDRM_plugin/mobidedrm.py
@@ -3,11 +3,11 @@
 
 # mobidedrm.py
 # Copyright © 2008 The Dark Reverser
-# Portions © 2008–2017 Apprentice Harper et al.
+# Portions © 2008–2020 Apprentice Harper et al.
 
 from __future__ import print_function
 __license__ = 'GPL v3'
-__version__ = u"0.42"
+__version__ = u"1.00"
 
 # This is a python script. You need a Python interpreter to run it.
 # For example, ActiveState Python, which exists for windows.
@@ -73,6 +73,7 @@ __version__ = u"0.42"
 #  0.40 - moved unicode_argv call inside main for Windows DeDRM compatibility
 #  0.41 - Fixed potential unicode problem in command line calls
 #  0.42 - Added GPL v3 licence. updated/removed some print statements
+#  3.00 - Added Python 3 compatibility for calibre 5.0
 
 import sys
 import os
@@ -93,7 +94,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -131,7 +132,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"mobidedrm.py"]
@@ -139,7 +140,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = 'utf-8'
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return sys.argv
 
 
 class DrmException(Exception):
@@ -153,12 +154,12 @@ class DrmException(Exception):
 # Implementation of Pukall Cipher 1
 def PC1(key, src, decryption=True):
     # if we can get it from alfcrypto, use that
-    try:
-        return Pukall_Cipher().PC1(key,src,decryption)
-    except NameError:
-        pass
-    except TypeError:
-        pass
+    #try:
+    #    return Pukall_Cipher().PC1(key,src,decryption)
+    #except NameError:
+    #    pass
+    #except TypeError:
+    #    pass
 
     # use slow python version, since Pukall_Cipher didn't load
     sum1 = 0;
@@ -167,28 +168,28 @@ def PC1(key, src, decryption=True):
     if len(key)!=16:
          DrmException (u"PC1: Bad key length")
     wkey = []
-    for i in xrange(8):
-        wkey.append(ord(key[i*2])<<8 | ord(key[i*2+1]))
-    dst = ""
-    for i in xrange(len(src)):
+    for i in range(8):
+        wkey.append(key[i*2]<<8 | key[i*2+1])
+    dst = b''
+    for i in range(len(src)):
         temp1 = 0;
         byteXorVal = 0;
-        for j in xrange(8):
+        for j in range(8):
             temp1 ^= wkey[j]
             sum2  = (sum2+j)*20021 + sum1
             sum1  = (temp1*346)&0xFFFF
             sum2  = (sum2+sum1)&0xFFFF
             temp1 = (temp1*20021+1)&0xFFFF
             byteXorVal ^= temp1 ^ sum2
-        curByte = ord(src[i])
+        curByte = src[i]
         if not decryption:
             keyXorVal = curByte * 257;
         curByte = ((curByte ^ (byteXorVal >> 8)) ^ byteXorVal) & 0xFF
         if decryption:
             keyXorVal = curByte * 257;
-        for j in xrange(8):
+        for j in range(8):
             wkey[j] ^= keyXorVal;
-        dst+=chr(curByte)
+        dst+=bytes([curByte])
     return dst
 
 def checksumPid(s):
@@ -200,7 +201,7 @@ def checksumPid(s):
     for i in (0,1):
         b = crc & 0xff
         pos = (b // l) ^ (b % l)
-        res += letters[pos%l]
+        res += letters[pos%l].encode('ascii')
         crc >>= 8
     return res
 
@@ -210,7 +211,7 @@ def getSizeOfTrailingDataEntries(ptr, size, flags):
         if size <= 0:
             return result
         while True:
-            v = ord(ptr[size-1])
+            v = ptr[size-1]
             result |= (v & 0x7F) << bitpos
             bitpos += 7
             size -= 1
@@ -226,7 +227,7 @@ def getSizeOfTrailingDataEntries(ptr, size, flags):
     # if multibyte data is included in the encryped data, we'll
     # have already cleared this flag.
     if flags & 1:
-        num += (ord(ptr[size - num - 1]) & 0x3) + 1
+        num += (ptr[size - num - 1] & 0x3) + 1
     return num
 
 
@@ -253,10 +254,10 @@ class MobiBook:
             print(u"AlfCrypto not found. Using python PC1 implementation.")
 
         # initial sanity check on file
-        self.data_file = file(infile, 'rb').read()
+        self.data_file = open(infile, 'rb').read()
         self.mobi_data = ''
         self.header = self.data_file[0:78]
-        if self.header[0x3C:0x3C+8] != 'BOOKMOBI' and self.header[0x3C:0x3C+8] != 'TEXtREAd':
+        if self.header[0x3C:0x3C+8] != b'BOOKMOBI' and self.header[0x3C:0x3C+8] != b'TEXtREAd':
             raise DrmException(u"Invalid file format")
         self.magic = self.header[0x3C:0x3C+8]
         self.crypto_type = -1
@@ -264,7 +265,7 @@ class MobiBook:
         # build up section offset and flag info
         self.num_sections, = struct.unpack('>H', self.header[76:78])
         self.sections = []
-        for i in xrange(self.num_sections):
+        for i in range(self.num_sections):
             offset, a1,a2,a3,a4 = struct.unpack('>LBBBB', self.data_file[78+i*8:78+i*8+8])
             flags, val = a1, a2<<16|a3<<8|a4
             self.sections.append( (offset, flags, val) )
@@ -304,24 +305,24 @@ class MobiBook:
             exth = ''
             if exth_flag & 0x40:
                 exth = self.sect[16 + self.mobi_length:]
-            if (len(exth) >= 12) and (exth[:4] == 'EXTH'):
+            if (len(exth) >= 12) and (exth[:4] == b'EXTH'):
                 nitems, = struct.unpack('>I', exth[8:12])
                 pos = 12
-                for i in xrange(nitems):
+                for i in range(nitems):
                     type, size = struct.unpack('>II', exth[pos: pos + 8])
                     content = exth[pos + 8: pos + size]
                     self.meta_array[type] = content
                     # reset the text to speech flag and clipping limit, if present
                     if type == 401 and size == 9:
                         # set clipping limit to 100%
-                        self.patchSection(0, '\144', 16 + self.mobi_length + pos + 8)
+                        self.patchSection(0, b'\144', 16 + self.mobi_length + pos + 8)
                     elif type == 404 and size == 9:
                         # make sure text to speech is enabled
-                        self.patchSection(0, '\0', 16 + self.mobi_length + pos + 8)
+                        self.patchSection(0, b'\0', 16 + self.mobi_length + pos + 8)
                     # print type, size, content, content.encode('hex')
                     pos += size
-        except:
-            pass
+        except Exception as e:
+            print(u"Cannot set meta_array: Error: {:s}".format(e.args[0]))
 
     def getBookTitle(self):
         codec_map = {
@@ -341,19 +342,19 @@ class MobiBook:
                 codec = codec_map[self.mobi_codepage]
         if title == '':
             title = self.header[:32]
-            title = title.split('\0')[0]
-        return unicode(title, codec)
+            title = title.split(b'\0')[0]
+        return title.decode(codec)
 
     def getPIDMetaInfo(self):
-        rec209 = ''
-        token = ''
+        rec209 = b''
+        token = b''
         if 209 in self.meta_array:
             rec209 = self.meta_array[209]
             data = rec209
             # The 209 data comes in five byte groups. Interpret the last four bytes
             # of each group as a big endian unsigned integer to get a key value
             # if that key exists in the meta_array, append its contents to the token
-            for i in xrange(0,len(data),5):
+            for i in range(0,len(data),5):
                 val,  = struct.unpack('>I',data[i+1:i+5])
                 sval = self.meta_array.get(val,'')
                 token += sval
@@ -373,13 +374,14 @@ class MobiBook:
 
     def parseDRM(self, data, count, pidlist):
         found_key = None
-        keyvec1 = '\x72\x38\x33\xB0\xB4\xF2\xE3\xCA\xDF\x09\x01\xD6\xE2\xE0\x3F\x96'
+        keyvec1 = b'\x72\x38\x33\xB0\xB4\xF2\xE3\xCA\xDF\x09\x01\xD6\xE2\xE0\x3F\x96'
         for pid in pidlist:
-            bigpid = pid.ljust(16,'\0')
+            bigpid = pid.ljust(16,b'\0')
+            bigpid = bigpid
             temp_key = PC1(keyvec1, bigpid, False)
-            temp_key_sum = sum(map(ord,temp_key)) & 0xff
+            temp_key_sum = sum(temp_key) & 0xff
             found_key = None
-            for i in xrange(count):
+            for i in range(count):
                 verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
                 if cksum == temp_key_sum:
                     cookie = PC1(temp_key, cookie)
@@ -393,8 +395,8 @@ class MobiBook:
             # Then try the default encoding that doesn't require a PID
             pid = '00000000'
             temp_key = keyvec1
-            temp_key_sum = sum(map(ord,temp_key)) & 0xff
-            for i in xrange(count):
+            temp_key_sum = sum(temp_key) & 0xff
+            for i in range(count):
                 verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
                 if cksum == temp_key_sum:
                     cookie = PC1(temp_key, cookie)
@@ -405,7 +407,7 @@ class MobiBook:
         return [found_key,pid]
 
     def getFile(self, outpath):
-        file(outpath,'wb').write(self.mobi_data)
+        open(outpath,'wb').write(self.mobi_data)
 
     def getBookType(self):
         if self.print_replica:
@@ -442,6 +444,7 @@ class MobiBook:
                 raise DrmException(u"Cannot decode library or rented ebooks.")
 
         goodpids = []
+        # print("DEBUG ==== pidlist = ", pidlist)
         for pid in pidlist:
             if len(pid)==10:
                 if checksumPid(pid[0:-2]) != pid:
@@ -452,6 +455,8 @@ class MobiBook:
             else:
                 print(u"Warning: PID {0} has wrong number of digits".format(pid))
 
+        # print(u"======= DEBUG good pids = ", goodpids)
+
         if self.crypto_type == 1:
             t1_keyvec = 'QDCVEPMU675RUBSZ'
             if self.magic == 'TEXtREAd':
@@ -471,9 +476,9 @@ class MobiBook:
             if not found_key:
                 raise DrmException(u"No key found in {0:d} keys tried.".format(len(goodpids)))
             # kill the drm keys
-            self.patchSection(0, '\0' * drm_size, drm_ptr)
+            self.patchSection(0, b'\0' * drm_size, drm_ptr)
             # kill the drm pointers
-            self.patchSection(0, '\xff' * 4 + '\0' * 12, 0xA8)
+            self.patchSection(0, b'\xff' * 4 + b'\0' * 12, 0xA8)
 
         if pid=='00000000':
             print(u"File has default encryption, no specific key needed.")
@@ -481,13 +486,13 @@ class MobiBook:
             print(u"File is encoded with PID {0}.".format(checksumPid(pid)))
 
         # clear the crypto type
-        self.patchSection(0, "\0" * 2, 0xC)
+        self.patchSection(0, b'\0' * 2, 0xC)
 
         # decrypt sections
         print(u"Decrypting. Please wait . . .", end=' ')
         mobidataList = []
         mobidataList.append(self.data_file[:self.sections[1][0]])
-        for i in xrange(1, self.records+1):
+        for i in range(1, self.records+1):
             data = self.loadSection(i)
             extra_size = getSizeOfTrailingDataEntries(data, len(data), self.extra_data_flags)
             if i%100 == 0:
@@ -501,7 +506,7 @@ class MobiBook:
                 mobidataList.append(data[-extra_size:])
         if self.num_sections > self.records+1:
             mobidataList.append(self.data_file[self.sections[self.records+1][0]:])
-        self.mobi_data = "".join(mobidataList)
+        self.mobi_data = b''.join(mobidataList)
         print(u"done")
         return
 
@@ -531,8 +536,8 @@ def cli_main():
             pidlist = []
         try:
             stripped_file = getUnencryptedBook(infile, pidlist)
-            file(outfile, 'wb').write(stripped_file)
-        except DrmException, e:
+            open(outfile, 'wb').write(stripped_file)
+        except DrmException as e:
             print(u"MobiDeDRM v{0} Error: {1:s}".format(__version__,e.args[0]))
             return 1
     return 0
diff --git a/DeDRM_plugin/prefs.py b/DeDRM_plugin/prefs.py
index c1bfcb9..cdbb189 100644
--- a/DeDRM_plugin/prefs.py
+++ b/DeDRM_plugin/prefs.py
@@ -101,9 +101,9 @@ def convertprefs(always = False):
                 keyname = u"{0}_{1}".format(name.strip(),ccn.strip()[-4:])
                 keyvalue = generate_key(name, ccn)
                 userkeys.append([keyname,keyvalue])
-            except Exception, e:
+            except Exception as e:
                 traceback.print_exc()
-                print e.args[0]
+                print(e.args[0])
                 pass
         return userkeys
 
@@ -118,9 +118,9 @@ def convertprefs(always = False):
                 keyname = u"{0}_{1}".format(name.strip(),cc.strip()[-4:])
                 keyvalue = getuser_key(name,cc).encode('hex')
                 userkeys.append([keyname,keyvalue])
-            except Exception, e:
+            except Exception as e:
                 traceback.print_exc()
-                print e.args[0]
+                print(e.args[0])
                 pass
         return userkeys
 
@@ -161,7 +161,7 @@ def convertprefs(always = False):
         return
 
 
-    print u"{0} v{1}: Importing configuration data from old DeDRM plugins".format(PLUGIN_NAME, PLUGIN_VERSION)
+    print(u"{0} v{1}: Importing configuration data from old DeDRM plugins".format(PLUGIN_NAME, PLUGIN_VERSION))
 
     IGNOBLEPLUGINNAME = "Ignoble Epub DeDRM"
     EREADERPLUGINNAME = "eReader PDB 2 PML"
@@ -177,7 +177,7 @@ def convertprefs(always = False):
     sc = config['plugin_customization']
     val = sc.pop(IGNOBLEPLUGINNAME, None)
     if val is not None:
-        print u"{0} v{1}: Converting old Ignoble plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION)
+        print(u"{0} v{1}: Converting old Ignoble plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION))
         priorkeycount = len(dedrmprefs['bandnkeys'])
         userkeys = parseIgnobleString(str(val))
         for keypair in userkeys:
@@ -185,7 +185,7 @@ def convertprefs(always = False):
             value = keypair[1]
             dedrmprefs.addnamedvaluetoprefs('bandnkeys', name, value)
         addedkeycount = len(dedrmprefs['bandnkeys'])-priorkeycount
-        print u"{0} v{1}: {2:d} Barnes and Noble {3} imported from old Ignoble plugin configuration string".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys")
+        print(u"{0} v{1}: {2:d} Barnes and Noble {3} imported from old Ignoble plugin configuration string".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
@@ -193,7 +193,7 @@ def convertprefs(always = False):
     # old string to stored keys... get that personal data out of plain sight.
     val = sc.pop(EREADERPLUGINNAME, None)
     if val is not None:
-        print u"{0} v{1}: Converting old eReader plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION)
+        print(u"{0} v{1}: Converting old eReader plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION))
         priorkeycount = len(dedrmprefs['ereaderkeys'])
         userkeys = parseeReaderString(str(val))
         for keypair in userkeys:
@@ -201,14 +201,14 @@ def convertprefs(always = False):
             value = keypair[1]
             dedrmprefs.addnamedvaluetoprefs('ereaderkeys', name, value)
         addedkeycount = len(dedrmprefs['ereaderkeys'])-priorkeycount
-        print u"{0} v{1}: {2:d} eReader {3} imported from old eReader plugin configuration string".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys")
+        print(u"{0} v{1}: {2:d} eReader {3} imported from old eReader plugin configuration string".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
     # get old Kindle plugin configuration string
     val = sc.pop(OLDKINDLEPLUGINNAME, None)
     if val is not None:
-        print u"{0} v{1}: Converting old Kindle plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION)
+        print(u"{0} v{1}: Converting old Kindle plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION))
         priorpidcount = len(dedrmprefs['pids'])
         priorserialcount = len(dedrmprefs['serials'])
         pids, serials = parseKindleString(val)
@@ -218,7 +218,7 @@ def convertprefs(always = False):
             dedrmprefs.addvaluetoprefs('serials',serial)
         addedpidcount = len(dedrmprefs['pids']) - priorpidcount
         addedserialcount = len(dedrmprefs['serials']) - priorserialcount
-        print u"{0} v{1}: {2:d} {3} and {4:d} {5} imported from old Kindle plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION, addedpidcount, u"PID" if addedpidcount==1 else u"PIDs", addedserialcount, u"serial number" if addedserialcount==1 else u"serial numbers")
+        print(u"{0} v{1}: {2:d} {3} and {4:d} {5} imported from old Kindle plugin configuration string.".format(PLUGIN_NAME, PLUGIN_VERSION, addedpidcount, u"PID" if addedpidcount==1 else u"PIDs", addedserialcount, u"serial number" if addedserialcount==1 else u"serial numbers"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
@@ -234,7 +234,7 @@ def convertprefs(always = False):
         dedrmprefs.addnamedvaluetoprefs('bandnkeys', name, value)
     addedkeycount = len(dedrmprefs['bandnkeys'])-priorkeycount
     if addedkeycount > 0:
-        print u"{0} v{1}: {2:d} Barnes and Noble {3} imported from config folder.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key file" if addedkeycount==1 else u"key files")
+        print(u"{0} v{1}: {2:d} Barnes and Noble {3} imported from config folder.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key file" if addedkeycount==1 else u"key files"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
@@ -247,7 +247,7 @@ def convertprefs(always = False):
         dedrmprefs.addnamedvaluetoprefs('adeptkeys', name, value)
     addedkeycount = len(dedrmprefs['adeptkeys'])-priorkeycount
     if addedkeycount > 0:
-        print u"{0} v{1}: {2:d} Adobe Adept {3} imported from config folder.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"keyfile" if addedkeycount==1 else u"keyfiles")
+        print(u"{0} v{1}: {2:d} Adobe Adept {3} imported from config folder.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"keyfile" if addedkeycount==1 else u"keyfiles"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
@@ -260,7 +260,7 @@ def convertprefs(always = False):
         addedkeycount = len(dedrmprefs['bandnkeys']) - priorkeycount
         # no need to delete old prefs, since they contain no recoverable private data
         if addedkeycount > 0:
-            print u"{0} v{1}: {2:d} Barnes and Noble {3} imported from Ignoble plugin preferences.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys")
+            print(u"{0} v{1}: {2:d} Barnes and Noble {3} imported from Ignoble plugin preferences.".format(PLUGIN_NAME, PLUGIN_VERSION, addedkeycount, u"key" if addedkeycount==1 else u"keys"))
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs(False)
 
@@ -277,19 +277,19 @@ def convertprefs(always = False):
             dedrmprefs.addvaluetoprefs('serials',serial)
     addedpidcount = len(dedrmprefs['pids']) - priorpidcount
     if addedpidcount > 0:
-        print u"{0} v{1}: {2:d} {3} imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, addedpidcount, u"PID" if addedpidcount==1 else u"PIDs")
+        print(u"{0} v{1}: {2:d} {3} imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, addedpidcount, u"PID" if addedpidcount==1 else u"PIDs"))
     addedserialcount = len(dedrmprefs['serials']) - priorserialcount
     if addedserialcount > 0:
-        print u"{0} v{1}: {2:d} {3} imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, addedserialcount, u"serial number" if addedserialcount==1 else u"serial numbers")
+        print(u"{0} v{1}: {2:d} {3} imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, addedserialcount, u"serial number" if addedserialcount==1 else u"serial numbers"))
     try:
         if 'wineprefix' in kindleprefs and kindleprefs['wineprefix'] != "":
             dedrmprefs.set('adobewineprefix',kindleprefs['wineprefix'])
             dedrmprefs.set('kindlewineprefix',kindleprefs['wineprefix'])
-            print u"{0} v{1}: WINEPREFIX ‘(2)’ imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, kindleprefs['wineprefix'])
+            print(u"{0} v{1}: WINEPREFIX ‘(2)’ imported from Kindle plugin preferences".format(PLUGIN_NAME, PLUGIN_VERSION, kindleprefs['wineprefix']))
     except:
         traceback.print_exc()
 
 
     # Make the json write all the prefs to disk
     dedrmprefs.writeprefs()
-    print u"{0} v{1}: Finished setting up configuration data.".format(PLUGIN_NAME, PLUGIN_VERSION)
+    print(u"{0} v{1}: Finished setting up configuration data.".format(PLUGIN_NAME, PLUGIN_VERSION))
diff --git a/DeDRM_plugin/scriptinterface.py b/DeDRM_plugin/scriptinterface.py
index bcdf0a7..25f23ad 100644
--- a/DeDRM_plugin/scriptinterface.py
+++ b/DeDRM_plugin/scriptinterface.py
@@ -6,13 +6,13 @@ from __future__ import print_function
 import sys
 import os
 import re
-import ineptepub
-import ignobleepub
-import epubtest
-import zipfix
-import ineptpdf
-import erdr2pml
-import k4mobidedrm
+import calibre_plugins.dedrm.ineptepub
+import calibre_plugins.dedrm.ignobleepub
+import calibre_plugins.dedrm.epubtest
+import calibre_plugins.dedrm.zipfix
+import calibre_plugins.dedrm.ineptpdf
+import calibre_plugins.dedrm.erdr2pml
+import calibre_plugins.dedrm.k4mobidedrm
 import traceback
 
 def decryptepub(infile, outdir, rscpath):
@@ -46,7 +46,7 @@ def decryptepub(infile, outdir, rscpath):
                     if rv == 0:
                         print("Decrypted Adobe ePub with key file {0}".format(filename))
                         break
-                except Exception, e:
+                except Exception as e:
                     errlog += traceback.format_exc()
                     errlog += str(e)
                     rv = 1
@@ -66,7 +66,7 @@ def decryptepub(infile, outdir, rscpath):
                     if rv == 0:
                         print("Decrypted B&N ePub with key file {0}".format(filename))
                         break
-                except Exception, e:
+                except Exception as e:
                     errlog += traceback.format_exc()
                     errlog += str(e)
                     rv = 1
@@ -104,7 +104,7 @@ def decryptpdf(infile, outdir, rscpath):
                 rv = ineptpdf.decryptBook(userkey, infile, outfile)
                 if rv == 0:
                     break
-            except Exception, e:
+            except Exception as e:
                 errlog += traceback.format_exc()
                 errlog += str(e)
                 rv = 1
@@ -132,7 +132,7 @@ def decryptpdb(infile, outdir, rscpath):
                 return 1
             try:
                 rv = erdr2pml.decryptBook(infile, outpath, True, erdr2pml.getuser_key(name, cc8))
-            except Exception, e:
+            except Exception as e:
                 errlog += traceback.format_exc()
                 errlog += str(e)
                 rv = 1
@@ -193,7 +193,7 @@ def decryptk4mobi(infile, outdir, rscpath):
             androidFiles.append(dpath)
     try:
         rv = k4mobidedrm.decryptBook(infile, outdir, kDatabaseFiles, androidFiles, serialnums, pidnums)
-    except Exception, e:
+    except Exception as e:
         errlog += traceback.format_exc()
         errlog += str(e)
         rv = 1
diff --git a/DeDRM_plugin/simpleprefs.py b/DeDRM_plugin/simpleprefs.py
index 0809944..5524663 100644
--- a/DeDRM_plugin/simpleprefs.py
+++ b/DeDRM_plugin/simpleprefs.py
@@ -46,7 +46,7 @@ class SimplePrefs(object):
                     try :
                         data = file(filepath,'rb').read()
                         self.prefs[key] = data
-                    except Exception, e:
+                    except Exception as e:
                         pass
 
     def getPreferences(self):
@@ -71,7 +71,7 @@ class SimplePrefs(object):
                     else:
                         try:
                             file(filepath,'wb').write(data)
-                        except Exception, e:
+                        except Exception as e:
                             pass
         self.prefs = newprefs
         return
diff --git a/DeDRM_plugin/topazextract.py b/DeDRM_plugin/topazextract.py
index 7d91f2c..ca0101d 100644
--- a/DeDRM_plugin/topazextract.py
+++ b/DeDRM_plugin/topazextract.py
@@ -7,9 +7,10 @@
 # Changelog
 #  4.9  - moved unicode_argv call inside main for Windows DeDRM compatibility
 #  5.0  - Fixed potential unicode problem with command line interface
+#  6.0  - Added Python 3 compatibility for calibre 5.0
 
 from __future__ import print_function
-__version__ = '5.0'
+__version__ = '6.0'
 
 import sys
 import os, csv, getopt
@@ -17,7 +18,7 @@ import zlib, zipfile, tempfile, shutil
 import traceback
 from struct import pack
 from struct import unpack
-from alfcrypto import Topaz_Cipher
+from calibre_plugins.dedrm.alfcrypto import Topaz_Cipher
 
 class SafeUnbuffered:
     def __init__(self, stream):
@@ -26,7 +27,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -64,7 +65,7 @@ def unicode_argv():
             # Remove Python executable and commands if present
             start = argc.value - len(sys.argv)
             return [argv[i] for i in
-                    xrange(start, argc.value)]
+                    range(start, argc.value)]
         # if we don't have any arguments at all, just pass back script name
         # this should never happen
         return [u"mobidedrm.py"]
@@ -72,7 +73,7 @@ def unicode_argv():
         argvencoding = sys.stdin.encoding
         if argvencoding == None:
             argvencoding = 'utf-8'
-        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]
+        return argv
 
 #global switch
 debug = False
@@ -196,7 +197,7 @@ def decryptDkeyRecords(data,PID):
 
 class TopazBook:
     def __init__(self, filename):
-        self.fo = file(filename, 'rb')
+        self.fo = open(filename, 'rb')
         self.outdir = tempfile.mkdtemp()
         # self.outdir = 'rawdat'
         self.bookPayloadOffset = 0
@@ -319,7 +320,7 @@ class TopazBook:
         fixedimage=True
         try:
             keydata = self.getBookPayloadRecord('dkey', 0)
-        except DrmException, e:
+        except DrmException as e:
             print(u"no dkey record found, book may not be encrypted")
             print(u"attempting to extrct files without a book key")
             self.createBookDirectory()
@@ -345,7 +346,7 @@ class TopazBook:
             data = keydata
             try:
                 bookKeys+=decryptDkeyRecords(data,pid)
-            except DrmException, e:
+            except DrmException as e:
                 pass
             else:
                 bookKey = bookKeys[0]
@@ -357,7 +358,7 @@ class TopazBook:
 
         self.setBookKey(bookKey)
         self.createBookDirectory()
-        self.extractFiles() 
+        self.extractFiles()
         print(u"Successfully Extracted Topaz contents")
         if inCalibre:
             from calibre_plugins.dedrm import genbook
@@ -411,7 +412,7 @@ class TopazBook:
                     print(u".", end=' ')
                     record = self.getBookPayloadRecord(name,index)
                     if record != '':
-                        file(outputFile, 'wb').write(record)
+                        open(outputFile, 'wb').write(record)
                 print(u" ")
 
     def getFile(self, zipname):
@@ -454,7 +455,7 @@ def cli_main():
 
     try:
         opts, args = getopt.getopt(argv[1:], "k:p:s:x")
-    except getopt.GetoptError, err:
+    except getopt.GetoptError as err:
         print(u"Error in options or arguments: {0}".format(err.args[0]))
         usage(progname)
         return 1
@@ -513,7 +514,7 @@ def cli_main():
         # removing internal temporary directory of pieces
         tb.cleanup()
 
-    except DrmException, e:
+    except DrmException as e:
         print(u"Decryption failed\n{0}".format(traceback.format_exc()))
 
         try:
@@ -522,8 +523,8 @@ def cli_main():
             pass
         return 1
 
-    except Exception, e:
-        print(u"Decryption failed\m{0}".format(traceback.format_exc()))
+    except Exception as e:
+        print(u"Decryption failed\n{0}".format(traceback.format_exc()))
         try:
             tb.cleanup()
         except:
diff --git a/DeDRM_plugin/utilities.py b/DeDRM_plugin/utilities.py
index c62b043..56c64fd 100644
--- a/DeDRM_plugin/utilities.py
+++ b/DeDRM_plugin/utilities.py
@@ -3,7 +3,7 @@
 
 from __future__ import with_statement
 
-from ignoblekeygen import generate_key
+from calibre_plugins.dedrm.ignoblekeygen import generate_key
 
 __license__ = 'GPL v3'
 
@@ -21,8 +21,8 @@ DETAILED_MESSAGE = \
 
 def uStrCmp (s1, s2, caseless=False):
     import unicodedata as ud
-    str1 = s1 if isinstance(s1, unicode) else unicode(s1)
-    str2 = s2 if isinstance(s2, unicode) else unicode(s2)
+    str1 = s1 if isinstance(s1, unicode) else s1.decode('utf-8')
+    str2 = s2 if isinstance(s2, unicode) else s2.decode('utf-8')
     if caseless:
         return ud.normalize('NFC', str1.lower()) == ud.normalize('NFC', str2.lower())
     else:
diff --git a/DeDRM_plugin/wineutils.py b/DeDRM_plugin/wineutils.py
index 65435a2..c5d4dee 100644
--- a/DeDRM_plugin/wineutils.py
+++ b/DeDRM_plugin/wineutils.py
@@ -40,7 +40,7 @@ def WineGetKeys(scriptpath, extension, wineprefix=""):
         cmdline = cmdline.encode(sys.getfilesystemencoding())
         p2 = Process(cmdline, shell=True, bufsize=1, stdin=None, stdout=sys.stdout, stderr=STDOUT, close_fds=False)
         result = p2.wait("wait")
-    except Exception, e:
+    except Exception as e:
         print(u"{0} v{1}: Wine subprocess call error: {2}".format(PLUGIN_NAME, PLUGIN_VERSION, e.args[0]))
         if wineprefix != "" and os.path.exists(wineprefix):
             cmdline = u"WINEPREFIX=\"{2}\" wine C:\\Python27\\python.exe \"{0}\" \"{1}\"".format(scriptpath,outdirpath,wineprefix)
@@ -52,7 +52,7 @@ def WineGetKeys(scriptpath, extension, wineprefix=""):
            cmdline = cmdline.encode(sys.getfilesystemencoding())
            p2 = Process(cmdline, shell=True, bufsize=1, stdin=None, stdout=sys.stdout, stderr=STDOUT, close_fds=False)
            result = p2.wait("wait")
-        except Exception, e:
+        except Exception as e:
            print(u"{0} v{1}: Wine subprocess call error: {2}".format(PLUGIN_NAME, PLUGIN_VERSION, e.args[0]))
 
     # try finding winekeys anyway, even if above code errored
diff --git a/DeDRM_plugin/zipfilerugged.py b/DeDRM_plugin/zipfilerugged.py
index 4a55a69..d20dab6 100644
--- a/DeDRM_plugin/zipfilerugged.py
+++ b/DeDRM_plugin/zipfilerugged.py
@@ -2,10 +2,12 @@
 Read and write ZIP files.
 """
 import struct, os, time, sys, shutil
-import binascii, cStringIO, stat
+import binascii, stat
 import io
 import re
 
+from io import BytesIO
+
 try:
     import zlib # We may need its compression method
     crc32 = zlib.crc32
@@ -45,8 +47,8 @@ ZIP_DEFLATED = 8
 
 # The "end of central directory" structure, magic number, size, and indices
 # (section V.I in the format document)
-structEndArchive = "<4s4H2LH"
-stringEndArchive = "PK\005\006"
+structEndArchive = b"<4s4H2LH"
+stringEndArchive = b"PK\005\006"
 sizeEndCentDir = struct.calcsize(structEndArchive)
 
 _ECD_SIGNATURE = 0
@@ -64,8 +66,8 @@ _ECD_LOCATION = 9
 
 # The "central directory" structure, magic number, size, and indices
 # of entries in the structure (section V.F in the format document)
-structCentralDir = "<4s4B4HL2L5H2L"
-stringCentralDir = "PK\001\002"
+structCentralDir = b"<4s4B4HL2L5H2L"
+stringCentralDir = b"PK\001\002"
 sizeCentralDir = struct.calcsize(structCentralDir)
 
 # indexes of entries in the central directory structure
@@ -91,8 +93,8 @@ _CD_LOCAL_HEADER_OFFSET = 18
 
 # The "local file header" structure, magic number, size, and indices
 # (section V.A in the format document)
-structFileHeader = "<4s2B4HL2L2H"
-stringFileHeader = "PK\003\004"
+structFileHeader = b"<4s2B4HL2L2H"
+stringFileHeader = b"PK\003\004"
 sizeFileHeader = struct.calcsize(structFileHeader)
 
 _FH_SIGNATURE = 0
@@ -109,14 +111,14 @@ _FH_FILENAME_LENGTH = 10
 _FH_EXTRA_FIELD_LENGTH = 11
 
 # The "Zip64 end of central directory locator" structure, magic number, and size
-structEndArchive64Locator = "<4sLQL"
-stringEndArchive64Locator = "PK\x06\x07"
+structEndArchive64Locator = b"<4sLQL"
+stringEndArchive64Locator = b"PK\x06\x07"
 sizeEndCentDir64Locator = struct.calcsize(structEndArchive64Locator)
 
 # The "Zip64 end of central directory" record, magic number, size, and indices
 # (section V.G in the format document)
-structEndArchive64 = "<4sQ2H2L4Q"
-stringEndArchive64 = "PK\x06\x06"
+structEndArchive64 = b"<4sQ2H2L4Q"
+stringEndArchive64 = b"PK\x06\x06"
 sizeEndCentDir64 = struct.calcsize(structEndArchive64)
 
 _CD64_SIGNATURE = 0
@@ -275,7 +277,7 @@ class ZipInfo (object):
 
         # Terminate the file name at the first null byte.  Null bytes in file
         # names are used as tricks by viruses in archives.
-        null_byte = filename.find(chr(0))
+        null_byte = filename.find(b"\0")
         if null_byte >= 0:
             filename = filename[0:null_byte]
         # This is used to ensure paths in generated ZIP files always use
@@ -288,8 +290,8 @@ class ZipInfo (object):
         self.date_time = date_time      # year, month, day, hour, min, sec
         # Standard values:
         self.compress_type = ZIP_STORED # Type of compression for the file
-        self.comment = ""               # Comment for each file
-        self.extra = ""                 # ZIP extra data
+        self.comment = b""               # Comment for each file
+        self.extra = b""                 # ZIP extra data
         if sys.platform == 'win32':
             self.create_system = 0          # System which created ZIP archive
         else:
@@ -343,23 +345,13 @@ class ZipInfo (object):
         return header + filename + extra
 
     def _encodeFilenameFlags(self):
-        if isinstance(self.filename, unicode):
+        if isinstance(self.filename, bytes):
+            return self.filename, self.flag_bits
+        else:
             try:
                 return self.filename.encode('ascii'), self.flag_bits
             except UnicodeEncodeError:
                 return self.filename.encode('utf-8'), self.flag_bits | 0x800
-        else:
-            return self.filename, self.flag_bits
-
-    def _decodeFilename(self):
-        if self.flag_bits & 0x800:
-            try:
-                #print "decoding filename",self.filename
-                return self.filename.decode('utf-8')
-            except:
-                return self.filename
-        else:
-            return self.filename
 
     def _decodeExtra(self):
         # Try to decode the extra field.
@@ -377,20 +369,20 @@ class ZipInfo (object):
                 elif ln == 0:
                     counts = ()
                 else:
-                    raise RuntimeError, "Corrupt extra field %s"%(ln,)
+                    raise RuntimeError("Corrupt extra field %s"%(ln,))
 
                 idx = 0
 
                 # ZIP64 extension (large files and/or large archives)
-                if self.file_size in (0xffffffffffffffffL, 0xffffffffL):
+                if self.file_size in (0xffffffffffffffff, 0xffffffff):
                     self.file_size = counts[idx]
                     idx += 1
 
-                if self.compress_size == 0xFFFFFFFFL:
+                if self.compress_size == 0xFFFFFFFF:
                     self.compress_size = counts[idx]
                     idx += 1
 
-                if self.header_offset == 0xffffffffL:
+                if self.header_offset == 0xffffffff:
                     old = self.header_offset
                     self.header_offset = counts[idx]
                     idx+=1
@@ -481,9 +473,9 @@ class ZipExtFile(io.BufferedIOBase):
 
         if self._compress_type == ZIP_DEFLATED:
             self._decompressor = zlib.decompressobj(-15)
-        self._unconsumed = ''
+        self._unconsumed = b''
 
-        self._readbuffer = ''
+        self._readbuffer = b''
         self._offset = 0
 
         self._universal = 'U' in mode
@@ -514,10 +506,10 @@ class ZipExtFile(io.BufferedIOBase):
         if not self._universal:
             return io.BufferedIOBase.readline(self, limit)
 
-        line = ''
+        line = b''
         while limit < 0 or len(line) < limit:
             readahead = self.peek(2)
-            if readahead == '':
+            if readahead == b'':
                 return line
 
             #
@@ -564,7 +556,7 @@ class ZipExtFile(io.BufferedIOBase):
         If the argument is omitted, None, or negative, data is read and returned until EOF is reached..
         """
 
-        buf = ''
+        buf = b''
         while n < 0 or n is None or n > len(buf):
             data = self.read1(n)
             if len(data) == 0:
@@ -594,7 +586,7 @@ class ZipExtFile(io.BufferedIOBase):
             self._compress_left -= len(data)
 
             if data and self._decrypter is not None:
-                data = ''.join(map(self._decrypter, data))
+                data = b''.join(map(self._decrypter, data))
 
             if self._compress_type == ZIP_STORED:
                 self._readbuffer = self._readbuffer[self._offset:] + data
@@ -651,10 +643,10 @@ class ZipFile:
             pass
         elif compression == ZIP_DEFLATED:
             if not zlib:
-                raise RuntimeError,\
-                      "Compression requires the (missing) zlib module"
+                raise RuntimeError(
+                      "Compression requires the (missing) zlib module")
         else:
-            raise RuntimeError, "That compression method is not supported"
+            raise RuntimeError("That compression method is not supported")
 
         self._allowZip64 = allowZip64
         self._didModify = False
@@ -664,10 +656,10 @@ class ZipFile:
         self.compression = compression  # Method of compression
         self.mode = key = mode.replace('b', '')[0]
         self.pwd = None
-        self.comment = ''
+        self.comment = b''
 
         # Check if we were passed a file-like object
-        if isinstance(file, basestring):
+        if isinstance(file, str):
             self._filePassed = 0
             self.filename = file
             modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
@@ -699,7 +691,7 @@ class ZipFile:
             if not self._filePassed:
                 self.fp.close()
                 self.fp = None
-            raise RuntimeError, 'Mode must be "r", "w" or "a"'
+            raise RuntimeError('Mode must be "r", "w" or "a"')
 
     def __enter__(self):
         return self
@@ -723,9 +715,9 @@ class ZipFile:
         fp = self.fp
         endrec = _EndRecData(fp)
         if not endrec:
-            raise BadZipfile, "File is not a zip file"
+            raise BadZipfile("File is not a zip file")
         if self.debug > 1:
-            print endrec
+            print(endrec)
         size_cd = endrec[_ECD_SIZE]             # bytes in central directory
         offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
         self.comment = endrec[_ECD_COMMENT]     # archive comment
@@ -738,20 +730,20 @@ class ZipFile:
 
         if self.debug > 2:
             inferred = concat + offset_cd
-            print "given, inferred, offset", offset_cd, inferred, concat
+            print("given, inferred, offset", offset_cd, inferred, concat)
         # self.start_dir:  Position of start of central directory
         self.start_dir = offset_cd + concat
         fp.seek(self.start_dir, 0)
         data = fp.read(size_cd)
-        fp = cStringIO.StringIO(data)
+        fp = BytesIO(data)
         total = 0
         while total < size_cd:
             centdir = fp.read(sizeCentralDir)
             if centdir[0:4] != stringCentralDir:
-                raise BadZipfile, "Bad magic number for central directory"
+                raise BadZipfile("Bad magic number for central directory")
             centdir = struct.unpack(structCentralDir, centdir)
             if self.debug > 2:
-                print centdir
+                print(centdir)
             filename = fp.read(centdir[_CD_FILENAME_LENGTH])
             # Create ZipInfo instance to store file information
             x = ZipInfo(filename)
@@ -769,7 +761,6 @@ class ZipFile:
 
             x._decodeExtra()
             x.header_offset = x.header_offset + concat
-            x.filename = x._decodeFilename()
             self.filelist.append(x)
             self.NameToInfo[x.filename] = x
 
@@ -779,7 +770,7 @@ class ZipFile:
                      + centdir[_CD_COMMENT_LENGTH])
 
             if self.debug > 2:
-                print "total", total
+                print("total", total)
 
 
     def namelist(self):
@@ -796,10 +787,10 @@ class ZipFile:
 
     def printdir(self):
         """Print a table of contents for the zip file."""
-        print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
+        print("%-46s %19s %12s" % ("File Name", "Modified    ", "Size"))
         for zinfo in self.filelist:
             date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
-            print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
+            print("%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size))
 
     def testzip(self):
         """Read all the files and check the CRC."""
@@ -834,10 +825,10 @@ class ZipFile:
     def open(self, name, mode="r", pwd=None):
         """Return file-like object for 'name'."""
         if mode not in ("r", "U", "rU"):
-            raise RuntimeError, 'open() requires mode "r", "U", or "rU"'
+            raise RuntimeError('open() requires mode "r", "U", or "rU"')
         if not self.fp:
-            raise RuntimeError, \
-                  "Attempt to read ZIP archive that was already closed"
+            raise RuntimeError(
+                  "Attempt to read ZIP archive that was already closed")
 
         # Only open a new file for instances where we were not
         # given a file object in the constructor
@@ -859,7 +850,7 @@ class ZipFile:
         # Skip the file header:
         fheader = zef_file.read(sizeFileHeader)
         if fheader[0:4] != stringFileHeader:
-            raise BadZipfile, "Bad magic number for file header"
+            raise BadZipfile("Bad magic number for file header")
 
         fheader = struct.unpack(structFileHeader, fheader)
         fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
@@ -867,9 +858,9 @@ class ZipFile:
             zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
 
         if fname != zinfo.orig_filename:
-            raise BadZipfile, \
+            raise BadZipfile(
                       'File name in directory "%s" and header "%s" differ.' % (
-                          zinfo.orig_filename, fname)
+                          zinfo.orig_filename, fname))
 
         # check for encrypted flag & handle password
         is_encrypted = zinfo.flag_bits & 0x1
@@ -878,8 +869,8 @@ class ZipFile:
             if not pwd:
                 pwd = self.pwd
             if not pwd:
-                raise RuntimeError, "File %s is encrypted, " \
-                      "password required for extraction" % name
+                raise RuntimeError("File %s is encrypted, " \
+                      "password required for extraction" % name)
 
             zd = _ZipDecrypter(pwd)
             # The first 12 bytes in the cypher stream is an encryption header
@@ -956,7 +947,7 @@ class ZipFile:
             return targetpath
 
         source = self.open(member, pwd=pwd)
-        target = file(targetpath, "wb")
+        target = open(targetpath, "wb")
         shutil.copyfileobj(source, target)
         source.close()
         target.close()
@@ -967,18 +958,18 @@ class ZipFile:
         """Check for errors before writing a file to the archive."""
         if zinfo.filename in self.NameToInfo:
             if self.debug:      # Warning for duplicate names
-                print "Duplicate name:", zinfo.filename
+                print("Duplicate name:", zinfo.filename)
         if self.mode not in ("w", "a"):
-            raise RuntimeError, 'write() requires mode "w" or "a"'
+            raise RuntimeError('write() requires mode "w" or "a"')
         if not self.fp:
-            raise RuntimeError, \
-                  "Attempt to write ZIP archive that was already closed"
+            raise RuntimeError(
+                  "Attempt to write ZIP archive that was already closed")
         if zinfo.compress_type == ZIP_DEFLATED and not zlib:
-            raise RuntimeError, \
-                  "Compression requires the (missing) zlib module"
+            raise RuntimeError(
+                  "Compression requires the (missing) zlib module")
         if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
-            raise RuntimeError, \
-                  "That compression method is not supported"
+            raise RuntimeError(
+                  "That compression method is not supported")
         if zinfo.file_size > ZIP64_LIMIT:
             if not self._allowZip64:
                 raise LargeZipFile("Filesize would require ZIP64 extensions")
@@ -1006,7 +997,7 @@ class ZipFile:
         if isdir:
             arcname += '/'
         zinfo = ZipInfo(arcname, date_time)
-        zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
+        zinfo.external_attr = (st[0] & 0xFFFF) << 16      # Unix attributes
         if compress_type is None:
             zinfo.compress_type = self.compression
         else:
@@ -1076,7 +1067,7 @@ class ZipFile:
                             date_time=time.localtime(time.time())[:6])
 
             zinfo.compress_type = self.compression
-            zinfo.external_attr = 0600 << 16
+            zinfo.external_attr = 0x0600 << 16
         else:
             zinfo = zinfo_or_arcname
 
@@ -1141,7 +1132,7 @@ class ZipFile:
 
                 if zinfo.header_offset > ZIP64_LIMIT:
                     extra.append(zinfo.header_offset)
-                    header_offset = 0xffffffffL
+                    header_offset = 0xffffffff
                 else:
                     header_offset = zinfo.header_offset
 
@@ -1169,14 +1160,14 @@ class ZipFile:
                      0, zinfo.internal_attr, zinfo.external_attr,
                      header_offset)
                 except DeprecationWarning:
-                    print >>sys.stderr, (structCentralDir,
+                    print(structCentralDir,
                      stringCentralDir, create_version,
                      zinfo.create_system, extract_version, zinfo.reserved,
                      zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
                      zinfo.CRC, compress_size, file_size,
                      len(zinfo.filename), len(extra_data), len(zinfo.comment),
                      0, zinfo.internal_attr, zinfo.external_attr,
-                     header_offset)
+                     header_offset, sys.stderr)
                     raise
                 self.fp.write(centdir)
                 self.fp.write(filename)
@@ -1250,10 +1241,10 @@ class PyZipFile(ZipFile):
                 else:
                     basename = name
                 if self.debug:
-                    print "Adding package in", pathname, "as", basename
+                    print("Adding package in", pathname, "as", basename)
                 fname, arcname = self._get_codename(initname[0:-3], basename)
                 if self.debug:
-                    print "Adding", arcname
+                    print("Adding", arcname)
                 self.write(fname, arcname)
                 dirlist = os.listdir(pathname)
                 dirlist.remove("__init__.py")
@@ -1269,12 +1260,12 @@ class PyZipFile(ZipFile):
                         fname, arcname = self._get_codename(path[0:-3],
                                          basename)
                         if self.debug:
-                            print "Adding", arcname
+                            print("Adding", arcname)
                         self.write(fname, arcname)
             else:
                 # This is NOT a package directory, add its files at top level
                 if self.debug:
-                    print "Adding files from directory", pathname
+                    print("Adding files from directory", pathname)
                 for filename in os.listdir(pathname):
                     path = os.path.join(pathname, filename)
                     root, ext = os.path.splitext(filename)
@@ -1282,15 +1273,15 @@ class PyZipFile(ZipFile):
                         fname, arcname = self._get_codename(path[0:-3],
                                          basename)
                         if self.debug:
-                            print "Adding", arcname
+                            print("Adding", arcname)
                         self.write(fname, arcname)
         else:
             if pathname[-3:] != ".py":
-                raise RuntimeError, \
-                      'Files added with writepy() must end with ".py"'
+                raise RuntimeError(
+                      'Files added with writepy() must end with ".py"')
             fname, arcname = self._get_codename(pathname[0:-3], basename)
             if self.debug:
-                print "Adding file", arcname
+                print("Adding file", arcname)
             self.write(fname, arcname)
 
     def _get_codename(self, pathname, basename):
@@ -1310,11 +1301,11 @@ class PyZipFile(ZipFile):
              os.stat(file_pyc).st_mtime < os.stat(file_py).st_mtime:
             import py_compile
             if self.debug:
-                print "Compiling", file_py
+                print("Compiling", file_py)
             try:
                 py_compile.compile(file_py, file_pyc, None, True)
-            except py_compile.PyCompileError,err:
-                print err.msg
+            except py_compile.PyCompileError as err:
+                print(err.msg)
             fname = file_pyc
         else:
             fname = file_pyc
@@ -1337,12 +1328,12 @@ def main(args = None):
         args = sys.argv[1:]
 
     if not args or args[0] not in ('-l', '-c', '-e', '-t'):
-        print USAGE
+        print(USAGE)
         sys.exit(1)
 
     if args[0] == '-l':
         if len(args) != 2:
-            print USAGE
+            print(USAGE)
             sys.exit(1)
         zf = ZipFile(args[1], 'r')
         zf.printdir()
@@ -1350,15 +1341,15 @@ def main(args = None):
 
     elif args[0] == '-t':
         if len(args) != 2:
-            print USAGE
+            print(USAGE)
             sys.exit(1)
         zf = ZipFile(args[1], 'r')
         zf.testzip()
-        print "Done testing"
+        print("Done testing")
 
     elif args[0] == '-e':
         if len(args) != 3:
-            print USAGE
+            print(USAGE)
             sys.exit(1)
 
         zf = ZipFile(args[1], 'r')
@@ -1378,7 +1369,7 @@ def main(args = None):
 
     elif args[0] == '-c':
         if len(args) < 3:
-            print USAGE
+            print(USAGE)
             sys.exit(1)
 
         def addToZip(zf, path, zippath):
diff --git a/DeDRM_plugin/zipfix.py b/DeDRM_plugin/zipfix.py
index d3371f2..190cf44 100644
--- a/DeDRM_plugin/zipfix.py
+++ b/DeDRM_plugin/zipfix.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-# zipfix.py, version 1.1
-# Copyright © 2010-2013 by some_updates, DiapDealer and Apprentice Alf
+# zipfix.py
+# Copyright © 2010-2020 by some_updates, DiapDealer and Apprentice Alf
 
 # Released under the terms of the GNU General Public Licence, version 3
 # <http://www.gnu.org/licenses/>
@@ -10,6 +10,7 @@
 # Revision history:
 #   1.0 - Initial release
 #   1.1 - Updated to handle zip file metadata correctly
+#   2.0 - Added Python 3 compatibility for calibre 5.0
 
 """
 Re-write zip (or ePub) fixing problems with file names (and mimetype entry).
@@ -21,7 +22,7 @@ __version__ = "1.1"
 
 import sys
 import zlib
-import zipfilerugged
+import calibre_plugins.dedrm.zipfilerugged as zipfilerugged
 import os
 import os.path
 import getopt
@@ -49,7 +50,7 @@ class fixZip:
         self.inzip = zipfilerugged.ZipFile(zinput,'r')
         self.outzip = zipfilerugged.ZipFile(zoutput,'w')
         # open the input zip for reading only as a raw file
-        self.bzf = file(zinput,'rb')
+        self.bzf = open(zinput,'rb')
 
     def getlocalname(self, zi):
         local_header_offset = zi.header_offset
@@ -115,7 +116,7 @@ class fixZip:
         # if epub write mimetype file first, with no compression
         if self.ztype == 'epub':
             # first get a ZipInfo with current time and no compression
-            mimeinfo = ZipInfo('mimetype',compress_type=zipfilerugged.ZIP_STORED)
+            mimeinfo = ZipInfo(b'mimetype',compress_type=zipfilerugged.ZIP_STORED)
             mimeinfo.internal_attr = 1 # text file
             try:
                 # if the mimetype is present, get its info, including time-stamp
@@ -129,7 +130,7 @@ class fixZip:
                 mimeinfo.create_system = oldmimeinfo.create_system
             except:
                 pass
-            self.outzip.writestr(mimeinfo, _MIMETYPE)
+            self.outzip.writestr(mimeinfo, _MIMETYPE.encode('ascii'))
 
         # write the rest of the files
         for zinfo in self.inzip.infolist():
@@ -171,7 +172,7 @@ def repairBook(infile, outfile):
         fr = fixZip(infile, outfile)
         fr.fix()
         return 0
-    except Exception, e:
+    except Exception as e:
         print("Error Occurred ", e)
         return 2
 
diff --git a/Obok_plugin/action.py b/Obok_plugin/action.py
index a0b63a6..802a833 100644
--- a/Obok_plugin/action.py
+++ b/Obok_plugin/action.py
@@ -6,13 +6,14 @@ __license__   = 'GPL v3'
 __docformat__ = 'restructuredtext en'
 
 
+import codecs
 import os, traceback, zipfile
 
 try:
     from PyQt5.Qt import QToolButton, QUrl
 except ImportError:
     from PyQt4.Qt import QToolButton, QUrl
- 
+
 from calibre.gui2 import open_url, question_dialog
 from calibre.gui2.actions import InterfaceAction
 from calibre.utils.config import config_dir
@@ -24,7 +25,7 @@ from calibre.ebooks.metadata.meta import get_metadata
 from calibre_plugins.obok_dedrm.dialogs import (SelectionDialog, DecryptAddProgressDialog,
                                                 AddEpubFormatsProgressDialog, ResultsSummaryDialog)
 from calibre_plugins.obok_dedrm.config import plugin_prefs as cfg
-from calibre_plugins.obok_dedrm.__init__ import (PLUGIN_NAME, PLUGIN_SAFE_NAME, 
+from calibre_plugins.obok_dedrm.__init__ import (PLUGIN_NAME, PLUGIN_SAFE_NAME,
                                 PLUGIN_VERSION, PLUGIN_DESCRIPTION, HELPFILE_NAME)
 from calibre_plugins.obok_dedrm.utilities import (
                             get_icon, set_plugin_icon_resources, showErrorDlg, format_plural,
@@ -53,7 +54,7 @@ class InterfacePluginAction(InterfaceAction):
     def genesis(self):
         icon_resources = self.load_resources(PLUGIN_ICONS)
         set_plugin_icon_resources(PLUGIN_NAME, icon_resources)
-        
+
         self.qaction.setIcon(get_icon(PLUGIN_ICONS[0]))
         self.qaction.triggered.connect(self.launchObok)
         self.gui.keyboard.finalize()
@@ -106,10 +107,10 @@ class InterfacePluginAction(InterfaceAction):
         # Get a list of Kobo titles
         books = self.build_book_list()
         if len(books) < 1:
-            msg = _('<p>No books found in Kobo Library\nAre you sure it\'s installed\configured\synchronized?')
+            msg = _('<p>No books found in Kobo Library\nAre you sure it\'s installed/configured/synchronized?')
             showErrorDlg(msg, None)
             return
-        
+
         # Check to see if a key can be retrieved using the legacy obok method.
         legacy_key = legacy_obok().get_legacy_cookie_id
         if legacy_key is not None:
@@ -154,7 +155,7 @@ class InterfacePluginAction(InterfaceAction):
         # Close Kobo Library object
         self.library.close()
 
-        # If we have decrypted books to work with, feed the list of decrypted books details 
+        # If we have decrypted books to work with, feed the list of decrypted books details
         # and the callback function (self.add_new_books) to the ProgressDialog dispatcher.
         if len(self.books_to_add):
             d = DecryptAddProgressDialog(self.gui, self.books_to_add, self.add_new_books, self.db, 'calibre',
@@ -212,7 +213,7 @@ class InterfacePluginAction(InterfaceAction):
     def get_decrypted_kobo_books(self, book):
         '''
         This method is a call-back function used by DecryptAddProgressDialog in dialogs.py to decrypt Kobo books
-        
+
         :param book: A KoboBook object that is to be decrypted.
         '''
         print (_('{0} - Decrypting {1}').format(PLUGIN_NAME + ' v' + PLUGIN_VERSION, book.title))
@@ -233,7 +234,7 @@ class InterfacePluginAction(InterfaceAction):
         '''
         This method is a call-back function used by DecryptAddProgressDialog in dialogs.py to add books to calibre
         (It's set up to handle multiple books, but will only be fed books one at a time by DecryptAddProgressDialog)
-        
+
         :param books_to_add: List of calibre bookmaps (created in get_decrypted_kobo_books)
         '''
         added = self.db.add_books(books_to_add, add_duplicates=False, run_hooks=False)
@@ -253,7 +254,7 @@ class InterfacePluginAction(InterfaceAction):
     def add_epub_format(self, book_id, mi, path):
         '''
         This method is a call-back function used by AddEpubFormatsProgressDialog in dialogs.py
-        
+
         :param book_id: calibre ID of the book to add the encrypted epub to.
         :param mi: calibre metadata object
         :param path: path to the decrypted epub (temp file)
@@ -281,7 +282,7 @@ class InterfacePluginAction(InterfaceAction):
                 self.formats_to_add.append((home_id, mi, tmp_file))
             else:
                 self.no_home_for_book.append(mi)
-        # If we found homes for decrypted epubs in existing calibre entries, feed the list of decrypted book 
+        # If we found homes for decrypted epubs in existing calibre entries, feed the list of decrypted book
         # details and the callback function (self.add_epub_format) to the ProgressDialog dispatcher.
         if self.formats_to_add:
             d = AddEpubFormatsProgressDialog(self.gui, self.formats_to_add, self.add_epub_format)
@@ -306,10 +307,10 @@ class InterfacePluginAction(InterfaceAction):
         sd = ResultsSummaryDialog(self.gui, caption, msg, log)
         sd.exec_()
         return
-    
+
     def ask_about_inserting_epubs(self):
         '''
-        Build question dialog with details about kobo books 
+        Build question dialog with details about kobo books
         that couldn't be added to calibre as new books.
         '''
         ''' Terisa: Improve the message
@@ -327,13 +328,13 @@ class InterfacePluginAction(InterfaceAction):
             msg = _('<p><b>{0}</b> -- not added because of {1} in your library.<br /><br />').format(self.duplicate_book_list[0][0].title, self.duplicate_book_list[0][2])
             msg += _('Would you like to try and add the EPUB format to an available calibre duplicate?<br /><br />')
             msg += _('NOTE: no pre-existing EPUB will be overwritten.')
-            
+
         return question_dialog(self.gui, caption, msg, det_msg)
 
     def find_a_home(self, ids):
         '''
         Find the ID of the first EPUB-Free duplicate available
-        
+
         :param ids: List of calibre IDs that might serve as a home.
         '''
         for id in ids:
@@ -373,7 +374,7 @@ class InterfacePluginAction(InterfaceAction):
         zin = zipfile.ZipFile(book.filename, 'r')
         #print ('Kobo library filename: {0}'.format(book.filename))
         for userkey in self.userkeys:
-            print (_('Trying key: '), userkey.encode('hex_codec'))
+            print (_('Trying key: '), codecs.encode(userkey, 'hex'))
             check = True
             try:
                 fileout = PersistentTemporaryFile('.epub', dir=self.tdir)
@@ -455,7 +456,7 @@ class InterfacePluginAction(InterfaceAction):
                     if cancelled_count > 0:
                         log += _('<p><b>Book imports cancelled by user:</b> {}</p>\n').format(cancelled_count)
                     return (msg, log)
-                log += _('<p><b>New EPUB formats inserted in existing calibre books:</b> {0}</p>\n').format(len(self.successful_format_adds))        
+                log += _('<p><b>New EPUB formats inserted in existing calibre books:</b> {0}</p>\n').format(len(self.successful_format_adds))
                 if self.successful_format_adds:
                     log += '<ul>\n'
                     for id, mi in self.successful_format_adds:
@@ -474,7 +475,7 @@ class InterfacePluginAction(InterfaceAction):
                         log += _('<p><b>Format imports cancelled by user:</b> {}</p>\n').format(cancelled_count)
                 return (msg, log)
             else:
-                
+
                 # Single book ... don't get fancy.
                 if self.ids_of_new_books:
                     title = self.ids_of_new_books[0][1].title
@@ -494,4 +495,4 @@ class InterfacePluginAction(InterfaceAction):
                     reason = _('of unknown reasons. Gosh I\'m embarrassed!')
                 msg = _('<p>{0} not added because {1}').format(title, reason)
                 return (msg, log)
- 
+
diff --git a/Obok_plugin/common_utils.py b/Obok_plugin/common_utils.py
index 0f2164a..babad1c 100644
--- a/Obok_plugin/common_utils.py
+++ b/Obok_plugin/common_utils.py
@@ -427,7 +427,7 @@ class KeyValueComboBox(QComboBox):
 
     def selected_key(self):
         for key, value in self.values.iteritems():
-            if value == unicode(self.currentText()).strip():
+            if value == self.currentText().strip():
                 return key
 
 
@@ -450,7 +450,7 @@ class KeyComboBox(QComboBox):
 
     def selected_key(self):
         for key, value in self.values.iteritems():
-            if key == unicode(self.currentText()).strip():
+            if key == self.currentText().strip():
                 return key
 
 
diff --git a/Obok_plugin/config.py b/Obok_plugin/config.py
index 8244b91..522b86a 100644
--- a/Obok_plugin/config.py
+++ b/Obok_plugin/config.py
@@ -75,7 +75,7 @@ class ConfigWidget(QWidget):
 
 
     def save_settings(self):
-        plugin_prefs['finding_homes_for_formats'] = unicode(self.find_homes.currentText())
+        plugin_prefs['finding_homes_for_formats'] = self.find_homes.currentText()
         plugin_prefs['kobo_serials'] = self.tmpserials
         plugin_prefs['kobo_directory'] = self.kobodirectory
 
@@ -165,7 +165,7 @@ class ManageKeysDialog(QDialog):
     def delete_key(self):
         if not self.listy.currentItem():
             return
-        keyname = unicode(self.listy.currentItem().text())
+        keyname = self.listy.currentItem().text()
         if not question_dialog(self, "{0} {1}: Confirm Delete".format(PLUGIN_NAME, PLUGIN_VERSION), u"Do you really want to delete the {1} <strong>{0}</strong>?".format(keyname, self.key_type_name), show_copy_button=False, default_yes=False):
             return
         self.plugin_keys.remove(keyname)
@@ -202,11 +202,11 @@ class AddSerialDialog(QDialog):
 
     @property
     def key_name(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     @property
     def key_value(self):
-        return unicode(self.key_ledit.text()).strip()
+        return self.key_ledit.text().strip()
 
     def accept(self):
         if len(self.key_name) == 0 or self.key_name.isspace():
diff --git a/Obok_plugin/obok/obok.py b/Obok_plugin/obok/obok.py
index 21ef14a..80bc058 100644
--- a/Obok_plugin/obok/obok.py
+++ b/Obok_plugin/obok/obok.py
@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
+# Version 4.0.0 September 2020
+# Python 3.0
+#
 # Version 3.2.5 December 2016
 # Improve detection of good text decryption.
 #
@@ -152,8 +155,8 @@
 """Manage all Kobo books, either encrypted or DRM-free."""
 from __future__ import print_function
 
-__version__ = '3.2.4'
-__about__ =  u"Obok v{0}\nCopyright © 2012-2016 Physisticated et al.".format(__version__)
+__version__ = '4.0.0'
+__about__ =  u"Obok v{0}\nCopyright © 2012-2020 Physisticated et al.".format(__version__)
 
 import sys
 import os
@@ -231,7 +234,7 @@ def _load_crypto_libcrypto():
                 raise ENCRYPTIONError(_('Failed to initialize AES key'))
 
         def decrypt(self, data):
-            clear = ''
+            clear = b''
             for i in range(0, len(data), 16):
                 out = create_string_buffer(16)
                 rv = AES_ecb_encrypt(data[i:i+16], out, self._key, 0)
@@ -276,7 +279,7 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,unicode):
+        if isinstance(data,bytes):
             data = data.encode(self.encoding,"replace")
         self.stream.write(data)
         self.stream.flush()
@@ -381,7 +384,7 @@ class KoboLibrary(object):
             print(self.newdb.name)
             olddb = open(kobodb, 'rb')
             self.newdb.write(olddb.read(18))
-            self.newdb.write('\x01\x01')
+            self.newdb.write(b'\x01\x01')
             olddb.read(2)
             self.newdb.write(olddb.read())
             olddb.close()
@@ -488,14 +491,14 @@ class KoboLibrary(object):
                 pass
             row = cursor.fetchone()
         return userids
-               
+
     def __getuserkeys (self, macaddr):
         userids = self.__getuserids()
         userkeys = []
         for hash in KOBO_HASH_KEYS:
-            deviceid = hashlib.sha256(hash + macaddr).hexdigest()
+            deviceid = hashlib.sha256((hash + macaddr).encode('ascii')).hexdigest()
             for userid in userids:
-                userkey = hashlib.sha256(deviceid + userid).hexdigest()
+                userkey = hashlib.sha256((deviceid + userid).encode('ascii')).hexdigest()
                 userkeys.append(binascii.a2b_hex(userkey[32:]))
         return userkeys
 
@@ -556,7 +559,7 @@ class KoboBook(object):
             # Convert relative URIs
             href = item.attrib['href']
             if not c.match(href):
-                href = string.join((basedir, href), '')
+                href = ''.join((basedir, href))
 
             # Update books we've found from the DB.
             if href in self._encryptedfiles:
@@ -606,57 +609,57 @@ class KoboFile(object):
             stride = 1
             print(u"Checking text:{0}:".format(contents[:10]))
             # check for byte order mark
-            if contents[:3]=="\xef\xbb\xbf":
+            if contents[:3]==b"\xef\xbb\xbf":
                 # seems to be utf-8 with BOM
                 print(u"Could be utf-8 with BOM")
                 textoffset = 3
-            elif contents[:2]=="\xfe\xff":
+            elif contents[:2]==b"\xfe\xff":
                 # seems to be utf-16BE
                 print(u"Could be  utf-16BE")
                 textoffset = 3
                 stride = 2
-            elif contents[:2]=="\xff\xfe":
+            elif contents[:2]==b"\xff\xfe":
                 # seems to be utf-16LE
                 print(u"Could be  utf-16LE")
                 textoffset = 2
                 stride = 2
             else:
                 print(u"Perhaps utf-8 without BOM")
-                
+
             # now check that the first few characters are in the ASCII range
-            for i in xrange(textoffset,textoffset+5*stride,stride):
-                if ord(contents[i])<32 or ord(contents[i])>127:
+            for i in range(textoffset,textoffset+5*stride,stride):
+                if contents[i]<32 or contents[i]>127:
                     # Non-ascii, so decryption probably failed
-                    print(u"Bad character at {0}, value {1}".format(i,ord(contents[i])))
+                    print(u"Bad character at {0}, value {1}".format(i,contents[i]))
                     raise ValueError
             print(u"Seems to be good text")
             return True
-            if contents[:5]=="<?xml" or contents[:8]=="\xef\xbb\xbf<?xml":
+            if contents[:5]==b"<?xml" or contents[:8]==b"\xef\xbb\xbf<?xml":
                 # utf-8
                 return True
-            elif contents[:14]=="\xfe\xff\x00<\x00?\x00x\x00m\x00l":
+            elif contents[:14]==b"\xfe\xff\x00<\x00?\x00x\x00m\x00l":
                 # utf-16BE
                 return True
-            elif contents[:14]=="\xff\xfe<\x00?\x00x\x00m\x00l\x00":
+            elif contents[:14]==b"\xff\xfe<\x00?\x00x\x00m\x00l\x00":
                 # utf-16LE
                 return True
-            elif contents[:9]=="<!DOCTYPE" or contents[:12]=="\xef\xbb\xbf<!DOCTYPE":
+            elif contents[:9]==b"<!DOCTYPE" or contents[:12]==b"\xef\xbb\xbf<!DOCTYPE":
                 # utf-8 of weird <!DOCTYPE start
                 return True
-            elif contents[:22]=="\xfe\xff\x00<\x00!\x00D\x00O\x00C\x00T\x00Y\x00P\x00E":
+            elif contents[:22]==b"\xfe\xff\x00<\x00!\x00D\x00O\x00C\x00T\x00Y\x00P\x00E":
                 # utf-16BE of weird <!DOCTYPE start
                 return True
-            elif contents[:22]=="\xff\xfe<\x00!\x00D\x00O\x00C\x00T\x00Y\x00P\x00E\x00":
+            elif contents[:22]==b"\xff\xfe<\x00!\x00D\x00O\x00C\x00T\x00Y\x00P\x00E\x00":
                 # utf-16LE of weird <!DOCTYPE start
                 return True
             else:
                 print(u"Bad XML: {0}".format(contents[:8]))
                 raise ValueError
         elif self.mimetype == 'image/jpeg':
-            if contents[:3] == '\xff\xd8\xff':
+            if contents[:3] == b'\xff\xd8\xff':
                 return True
             else:
-                print(u"Bad JPEG: {0}".format(contents[:3].encode('hex')))
+                print(u"Bad JPEG: {0}".format(contents[:3].hex()))
                 raise ValueError()
         return False
 
@@ -690,7 +693,7 @@ def decrypt_book(book, lib):
         return 0
     result = 1
     for userkey in lib.userkeys:
-        print(u"Trying key: {0}".format(userkey.encode('hex_codec')))
+        print(u"Trying key: {0}".format(userkey.hex()))
         try:
             zout = zipfile.ZipFile(outname, "w", zipfile.ZIP_DEFLATED)
             for filename in zin.namelist():
@@ -735,7 +738,7 @@ def cli_main():
             print(u"{0}: {1}".format(i + 1, book.title))
         print(u"Or 'all'")
 
-        choice = raw_input(u"Convert book number... ")
+        choice = input(u"Convert book number... ")
         if choice == u'all':
             books = list(lib.books)
         else:
diff --git a/Obok_plugin/utilities.py b/Obok_plugin/utilities.py
index 62e305c..f81bd1c 100644
--- a/Obok_plugin/utilities.py
+++ b/Obok_plugin/utilities.py
@@ -7,21 +7,24 @@ __docformat__ = 'restructuredtext en'
 
 
 import os, struct, time
-from StringIO import StringIO
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
 from traceback import print_exc
 
 try:
     from PyQt5.Qt import (Qt, QDialog, QPixmap, QIcon, QLabel, QHBoxLayout, QFont, QTableWidgetItem)
 except ImportError:
     from PyQt4.Qt import (Qt, QDialog, QPixmap, QIcon, QLabel, QHBoxLayout, QFont, QTableWidgetItem)
-    
+
 from calibre.utils.config import config_dir
 from calibre.constants import iswindows, DEBUG
 from calibre import prints
 from calibre.gui2 import (error_dialog, gprefs)
 from calibre.gui2.actions import menu_action_unique_name
 
-from calibre_plugins.obok_dedrm.__init__ import (PLUGIN_NAME,  
+from calibre_plugins.obok_dedrm.__init__ import (PLUGIN_NAME,
                     PLUGIN_SAFE_NAME, PLUGIN_VERSION, PLUGIN_DESCRIPTION)
 
 plugin_ID = None
@@ -39,7 +42,7 @@ else:
     def convert_qvariant(x):
         vt = x.type()
         if vt == x.String:
-            return unicode(x.toString())
+            return x.toString()
         if vt == x.List:
             return [convert_qvariant(i) for i in x.toList()]
         return x.toPyObject()
@@ -62,7 +65,7 @@ except NameError:
 def format_plural(number, possessive=False):
     '''
     Cosmetic ditty to provide the proper string formatting variable to handle singular/plural situations
-    
+
     :param: number: variable that represents the count/len of something
     '''
     if not possessive:
@@ -141,7 +144,7 @@ def showErrorDlg(errmsg, parent, trcbk=False):
     '''
     if trcbk:
         error= ''
-        f=StringIO()     
+        f=StringIO()
         print_exc(file=f)
         error_mess = f.getvalue().splitlines()
         for line in error_mess:
diff --git a/Other_Tools/DRM_Key_Scripts/Barnes_and_Noble_ePubs/ignoblekey.pyw b/Other_Tools/DRM_Key_Scripts/Barnes_and_Noble_ePubs/ignoblekey.pyw
index dbadc5d..98ae209 100644
--- a/Other_Tools/DRM_Key_Scripts/Barnes_and_Noble_ePubs/ignoblekey.pyw
+++ b/Other_Tools/DRM_Key_Scripts/Barnes_and_Noble_ePubs/ignoblekey.pyw
@@ -4,7 +4,7 @@
 from __future__ import with_statement
 
 # ignoblekey.py
-# Copyright © 2015 Apprentice Alf and Apprentice Harper
+# Copyright © 2015-2020 Apprentice Harper et al.
 
 # Based on kindlekey.py, Copyright © 2010-2013 by some_updates and Apprentice Alf
 
@@ -14,13 +14,14 @@ from __future__ import with_statement
 # Revision history:
 #   1.0 - Initial release
 #   1.1 - remove duplicates and return last key as single key
+#   2.0 - Python 3
 
 """
 Get Barnes & Noble EPUB user key from nook Studio log file
 """
 
 __license__ = 'GPL v3'
-__version__ = "1.1"
+__version__ = "2.0"
 
 import sys
 import os
@@ -318,7 +319,7 @@ def gui_main():
                 keyfileout.write(key)
             success = True
             tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
-    except DrmException, e:
+    except DrmException as e:
         tkMessageBox.showerror(progname, u"Error: {0}".format(str(e)))
     except Exception:
         root.wm_state('normal')
diff --git a/make_release.py b/make_release.py
index e88c3cb..bedb956 100755
--- a/make_release.py
+++ b/make_release.py
@@ -13,10 +13,10 @@ import os
 import shutil
 
 
-DEDRM_SRC_DIR = 'DeDRM_Plugin'
-DEDRM_README= 'DeDRM_Plugin_ReadMe.txt'
+DEDRM_SRC_DIR = 'DeDRM_plugin'
+DEDRM_README= 'DeDRM_plugin_ReadMe.txt'
 OBOK_SRC_DIR = 'Obok_plugin'
-OBOK_README = 'Obok_plugin_ReadMe.txt'
+OBOK_README = 'obok_plugin_ReadMe.txt'
 RELEASE_DIR = 'release'
 
 def make_calibre_plugin():