More generic 3.0 changes, to be tested.

5 files changed, 79 insertions, 95 deletions

diff --git a/Obok_plugin/action.py b/Obok_plugin/action.py
index 802a833..e94204f 100644
--- a/Obok_plugin/action.py
+++ b/Obok_plugin/action.py
@@ -1,8 +1,8 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import (unicode_literals, division, absolute_import,
-                        print_function)
 
-__license__   = 'GPL v3'
+_license__   = 'GPL v3'
 __docformat__ = 'restructuredtext en'
 
 
diff --git a/Obok_plugin/common_utils.py b/Obok_plugin/common_utils.py
index babad1c..21b7f19 100644
--- a/Obok_plugin/common_utils.py
+++ b/Obok_plugin/common_utils.py
@@ -1,7 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import (unicode_literals, division, absolute_import,
-                        print_function)
 
 __license__   = 'GPL v3'
 __copyright__ = '2012, David Forrester <[email protected]>'
@@ -9,13 +8,7 @@ __docformat__ = 'restructuredtext en'
 
 import os, time, re, sys
 from datetime import datetime
-try:
-    from PyQt5.Qt import (Qt, QIcon, QPixmap, QLabel, QDialog, QHBoxLayout, QProgressBar,
-                          QTableWidgetItem, QFont, QLineEdit, QComboBox,
-                          QVBoxLayout, QDialogButtonBox, QStyledItemDelegate, QDateTime,
-                          QRegExpValidator, QRegExp, QDate, QDateEdit)
-except ImportError:
-    from PyQt4.Qt import (Qt, QIcon, QPixmap, QLabel, QDialog, QHBoxLayout, QProgressBar,
+from PyQt5.Qt import (Qt, QIcon, QPixmap, QLabel, QDialog, QHBoxLayout, QProgressBar,
                           QTableWidgetItem, QFont, QLineEdit, QComboBox,
                           QVBoxLayout, QDialogButtonBox, QStyledItemDelegate, QDateTime,
                           QRegExpValidator, QRegExp, QDate, QDateEdit)
diff --git a/Obok_plugin/config.py b/Obok_plugin/config.py
index 522b86a..2830dad 100644
--- a/Obok_plugin/config.py
+++ b/Obok_plugin/config.py
@@ -1,16 +1,10 @@
-# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import (unicode_literals, division, absolute_import,
-                        print_function)
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 
-try:
-    from PyQt5.Qt import (Qt, QGroupBox, QListWidget, QLineEdit, QDialogButtonBox, QWidget, QLabel, QDialog, QVBoxLayout, QAbstractItemView, QIcon, QHBoxLayout, QComboBox, QListWidgetItem, QFileDialog)
-except ImportError:
-    from PyQt4.Qt import (Qt, QGroupBox, QListWidget, QLineEdit, QDialogButtonBox, QWidget, QLabel, QDialog, QVBoxLayout, QAbstractItemView, QIcon, QHBoxLayout, QComboBox, QListWidgetItem, QFileDialog)
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
 
-try:
-    from PyQt5 import Qt as QtGui
-except ImportError:
-    from PyQt4 import QtGui
+from PyQt5.Qt import (Qt, QGroupBox, QListWidget, QLineEdit, QDialogButtonBox, QWidget, QLabel, QDialog, QVBoxLayout, QAbstractItemView, QIcon, QHBoxLayout, QComboBox, QListWidgetItem, QFileDialog)
+from PyQt5 import Qt as QtGui
 
 from calibre.gui2 import (error_dialog, question_dialog, info_dialog, open_url)
 from calibre.utils.config import JSONConfig, config_dir
@@ -50,25 +44,25 @@ class ConfigWidget(QWidget):
         self.find_homes.setCurrentIndex(index)
 
         self.serials_button = QtGui.QPushButton(self)
-        self.serials_button.setToolTip(_(u"Click to manage Kobo serial numbers for Kobo ebooks"))
-        self.serials_button.setText(u"Kobo devices serials")
+        self.serials_button.setToolTip(_("Click to manage Kobo serial numbers for Kobo ebooks"))
+        self.serials_button.setText("Kobo devices serials")
         self.serials_button.clicked.connect(self.edit_serials)
         layout.addWidget(self.serials_button)
 
         self.kobo_directory_button = QtGui.QPushButton(self)
-        self.kobo_directory_button.setToolTip(_(u"Click to specify the Kobo directory"))
-        self.kobo_directory_button.setText(u"Kobo directory")
+        self.kobo_directory_button.setToolTip(_("Click to specify the Kobo directory"))
+        self.kobo_directory_button.setText("Kobo directory")
         self.kobo_directory_button.clicked.connect(self.edit_kobo_directory)
         layout.addWidget(self.kobo_directory_button)
 
 
     def edit_serials(self):
-        d = ManageKeysDialog(self,u"Kobo device serial number",self.tmpserials, AddSerialDialog)
+        d = ManageKeysDialog(self,"Kobo device serial number",self.tmpserials, AddSerialDialog)
         d.exec_()
 
 
     def edit_kobo_directory(self):
-        tmpkobodirectory = QFileDialog.getExistingDirectory(self, u"Select Kobo directory", self.kobodirectory or "/home", QFileDialog.ShowDirsOnly)
+        tmpkobodirectory = QFileDialog.getExistingDirectory(self, "Select Kobo directory", self.kobodirectory or "/home", QFileDialog.ShowDirsOnly)
 
         if tmpkobodirectory != u"" and tmpkobodirectory is not None:
             self.kobodirectory = tmpkobodirectory
@@ -91,7 +85,7 @@ class ManageKeysDialog(QDialog):
         self.plugin_keys = plugin_keys
         self.create_key = create_key
         self.keyfile_ext = keyfile_ext
-        self.json_file = (keyfile_ext == u"k4i")
+        self.json_file = (keyfile_ext == "k4i")
 
         self.setWindowTitle("{0} {1}: Manage {2}s".format(PLUGIN_NAME, PLUGIN_VERSION, self.key_type_name))
 
@@ -99,13 +93,13 @@ class ManageKeysDialog(QDialog):
         layout = QVBoxLayout(self)
         self.setLayout(layout)
 
-        keys_group_box = QGroupBox(_(u"{0}s".format(self.key_type_name)), self)
+        keys_group_box = QGroupBox(_("{0}s".format(self.key_type_name)), self)
         layout.addWidget(keys_group_box)
         keys_group_box_layout = QHBoxLayout()
         keys_group_box.setLayout(keys_group_box_layout)
 
         self.listy = QListWidget(self)
-        self.listy.setToolTip(u"{0}s that will be used to decrypt ebooks".format(self.key_type_name))
+        self.listy.setToolTip("{0}s that will be used to decrypt ebooks".format(self.key_type_name))
         self.listy.setSelectionMode(QAbstractItemView.SingleSelection)
         self.populate_list()
         keys_group_box_layout.addWidget(self.listy)
@@ -114,12 +108,12 @@ class ManageKeysDialog(QDialog):
         keys_group_box_layout.addLayout(button_layout)
         self._add_key_button = QtGui.QToolButton(self)
         self._add_key_button.setIcon(QIcon(I('plus.png')))
-        self._add_key_button.setToolTip(u"Create new {0}".format(self.key_type_name))
+        self._add_key_button.setToolTip("Create new {0}".format(self.key_type_name))
         self._add_key_button.clicked.connect(self.add_key)
         button_layout.addWidget(self._add_key_button)
 
         self._delete_key_button = QtGui.QToolButton(self)
-        self._delete_key_button.setToolTip(_(u"Delete highlighted key"))
+        self._delete_key_button.setToolTip(_("Delete highlighted key"))
         self._delete_key_button.setIcon(QIcon(I('list_remove.png')))
         self._delete_key_button.clicked.connect(self.delete_key)
         button_layout.addWidget(self._delete_key_button)
@@ -155,7 +149,7 @@ class ManageKeysDialog(QDialog):
         new_key_value = d.key_value
         if new_key_value in self.plugin_keys:
             info_dialog(None, "{0} {1}: Duplicate {2}".format(PLUGIN_NAME, PLUGIN_VERSION,self.key_type_name),
-                        u"This {0} is already in the list of {0}s has not been added.".format(self.key_type_name), show=True)
+                        "This {0} is already in the list of {0}s has not been added.".format(self.key_type_name), show=True)
             return
 
         self.plugin_keys.append(d.key_value)
@@ -166,7 +160,7 @@ class ManageKeysDialog(QDialog):
         if not self.listy.currentItem():
             return
         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):
+        if not question_dialog(self, "{0} {1}: Confirm Delete".format(PLUGIN_NAME, PLUGIN_VERSION), "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)
 
@@ -177,7 +171,7 @@ class AddSerialDialog(QDialog):
     def __init__(self, parent=None,):
         QDialog.__init__(self, parent)
         self.parent = parent
-        self.setWindowTitle(u"{0} {1}: Add New eInk Kobo Serial Number".format(PLUGIN_NAME, PLUGIN_VERSION))
+        self.setWindowTitle("{0} {1}: Add New eInk Kobo Serial Number".format(PLUGIN_NAME, PLUGIN_VERSION))
         layout = QVBoxLayout(self)
         self.setLayout(layout)
 
@@ -188,9 +182,9 @@ class AddSerialDialog(QDialog):
 
         key_group = QHBoxLayout()
         data_group_box_layout.addLayout(key_group)
-        key_group.addWidget(QLabel(u"EInk Kobo Serial Number:", self))
+        key_group.addWidget(QLabel("EInk Kobo Serial Number:", self))
         self.key_ledit = QLineEdit("", self)
-        self.key_ledit.setToolTip(u"Enter an eInk Kobo serial number. EInk Kobo serial numbers are 13 characters long and usually start with a 'N'. Kobo Serial Numbers are case-sensitive, so be sure to enter the upper and lower case letters unchanged.")
+        self.key_ledit.setToolTip("Enter an eInk Kobo serial number. EInk Kobo serial numbers are 13 characters long and usually start with a 'N'. Kobo Serial Numbers are case-sensitive, so be sure to enter the upper and lower case letters unchanged.")
         key_group.addWidget(self.key_ledit)
 
         self.button_box = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
@@ -210,9 +204,9 @@ class AddSerialDialog(QDialog):
 
     def accept(self):
         if len(self.key_name) == 0 or self.key_name.isspace():
-            errmsg = u"Please enter an eInk Kindle Serial Number or click Cancel in the dialog."
+            errmsg = "Please enter an eInk Kindle Serial Number or click Cancel in the dialog."
             return error_dialog(None, "{0} {1}".format(PLUGIN_NAME, PLUGIN_VERSION), errmsg, show=True, show_copy_button=False)
         if len(self.key_name) != 13:
-            errmsg = u"EInk Kobo Serial Numbers must be 13 characters long. This is {0:d} characters long.".format(len(self.key_name))
+            errmsg = "EInk Kobo Serial Numbers must be 13 characters long. This is {0:d} characters long.".format(len(self.key_name))
             return error_dialog(None, "{0} {1}".format(PLUGIN_NAME, PLUGIN_VERSION), errmsg, show=True, show_copy_button=False)
         QDialog.accept(self)
diff --git a/Obok_plugin/obok/obok.py b/Obok_plugin/obok/obok.py
index 80bc058..d20f6dc 100644
--- a/Obok_plugin/obok/obok.py
+++ b/Obok_plugin/obok/obok.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 # Version 4.0.0 September 2020
@@ -156,7 +156,7 @@
 from __future__ import print_function
 
 __version__ = '4.0.0'
-__about__ =  u"Obok v{0}\nCopyright © 2012-2020 Physisticated et al.".format(__version__)
+__about__ =  "Obok v{0}\nCopyright © 2012-2020 Physisticated et al.".format(__version__)
 
 import sys
 import os
@@ -176,10 +176,10 @@ import tempfile
 can_parse_xml = True
 try:
   from xml.etree import ElementTree as ET
-  # print u"using xml.etree for xml parsing"
+  # print "using xml.etree for xml parsing"
 except ImportError:
   can_parse_xml = False
-  # print u"Cannot find xml.etree, disabling extraction of serial numbers"
+  # print "Cannot find xml.etree, disabling extraction of serial numbers"
 
 # List of all known hash keys
 KOBO_HASH_KEYS = ['88b3a2e13', 'XzUhGYdFp', 'NoCanLook','QJhwzAtXL']
@@ -279,10 +279,10 @@ class SafeUnbuffered:
         if self.encoding == None:
             self.encoding = "utf-8"
     def write(self, data):
-        if isinstance(data,bytes):
+        if isinstance(data,str):
             data = data.encode(self.encoding,"replace")
-        self.stream.write(data)
-        self.stream.flush()
+        self.stream.buffer.write(data)
+        self.stream.buffer.flush()
     def __getattr__(self, attr):
         return getattr(self.stream, attr)
 
@@ -312,9 +312,9 @@ class KoboLibrary(object):
         # step 1. check whether this looks like a real device
         if (device_path):
             # we got a device path
-            self.kobodir = os.path.join(device_path, u".kobo")
+            self.kobodir = os.path.join(device_path, ".kobo")
             # devices use KoboReader.sqlite
-            kobodb  = os.path.join(self.kobodir, u"KoboReader.sqlite")
+            kobodb  = os.path.join(self.kobodir, "KoboReader.sqlite")
             if (not(os.path.isfile(kobodb))):
                 # device path seems to be wrong, unset it
                 device_path = u""
@@ -326,22 +326,22 @@ class KoboLibrary(object):
             if (len(serials) == 0):
                 # we got a device path but no saved serial
                 # try to get the serial from the device
-                # print u"get_device_settings - device_path = {0}".format(device_path)
+                # print "get_device_settings - device_path = {0}".format(device_path)
                 # get serial from device_path/.adobe-digital-editions/device.xml
                 if can_parse_xml:
                     devicexml = os.path.join(device_path, '.adobe-digital-editions', 'device.xml')
-                    # print u"trying to load {0}".format(devicexml)
+                    # print "trying to load {0}".format(devicexml)
                     if (os.path.exists(devicexml)):
-                        # print u"trying to parse {0}".format(devicexml)
+                        # print "trying to parse {0}".format(devicexml)
                         xmltree = ET.parse(devicexml)
                         for node in xmltree.iter():
                             if "deviceSerial" in node.tag:
                                 serial = node.text
-                                # print u"found serial {0}".format(serial)
+                                # print "found serial {0}".format(serial)
                                 serials.append(serial)
                                 break
                     else:
-                        # print u"cannot get serials from device."
+                        # print "cannot get serials from device."
                         device_path = u""
                         self.kobodir = u""
                         kobodb  = u""
@@ -357,19 +357,19 @@ class KoboLibrary(object):
                     if sys.getwindowsversion().major > 5:
                         if 'LOCALAPPDATA' in os.environ.keys():
                             # Python 2.x does not return unicode env. Use Python 3.x
-                            self.kobodir = winreg.ExpandEnvironmentStrings(u"%LOCALAPPDATA%")
+                            self.kobodir = winreg.ExpandEnvironmentStrings("%LOCALAPPDATA%")
                     if (self.kobodir == u""):
                         if 'USERPROFILE' in os.environ.keys():
                             # Python 2.x does not return unicode env. Use Python 3.x
-                            self.kobodir = os.path.join(winreg.ExpandEnvironmentStrings(u"%USERPROFILE%"), u"Local Settings", u"Application Data")
-                    self.kobodir = os.path.join(self.kobodir, u"Kobo", u"Kobo Desktop Edition")
+                            self.kobodir = os.path.join(winreg.ExpandEnvironmentStrings("%USERPROFILE%"), "Local Settings", "Application Data")
+                    self.kobodir = os.path.join(self.kobodir, "Kobo", "Kobo Desktop Edition")
                 elif sys.platform.startswith('darwin'):
-                    self.kobodir = os.path.join(os.environ['HOME'], u"Library", u"Application Support", u"Kobo", u"Kobo Desktop Edition")
+                    self.kobodir = os.path.join(os.environ['HOME'], "Library", "Application Support", "Kobo", "Kobo Desktop Edition")
             #elif linux_path != None:
                 # Probably Linux, let's get the wine prefix and path to Kobo.
-            #   self.kobodir = os.path.join(linux_path, u"Local Settings", u"Application Data", u"Kobo", u"Kobo Desktop Edition")
+            #   self.kobodir = os.path.join(linux_path, "Local Settings", "Application Data", "Kobo", "Kobo Desktop Edition")
             # desktop versions use Kobo.sqlite
-            kobodb = os.path.join(self.kobodir, u"Kobo.sqlite")
+            kobodb = os.path.join(self.kobodir, "Kobo.sqlite")
             # check for existence of file
             if (not(os.path.isfile(kobodb))):
                 # give up here, we haven't found anything useful
@@ -377,7 +377,7 @@ class KoboLibrary(object):
                 kobodb  = u""
 
         if (self.kobodir != u""):
-            self.bookdir = os.path.join(self.kobodir, u"kepub")
+            self.bookdir = os.path.join(self.kobodir, "kepub")
             # make a copy of the database in a temporary file
             # so we can ensure it's not using WAL logging which sqlite3 can't do.
             self.newdb = tempfile.NamedTemporaryFile(mode='wb', delete=False)
@@ -437,7 +437,7 @@ class KoboLibrary(object):
 
     def __bookfile (self, volumeid):
         """The filename needed to open a given book."""
-        return os.path.join(self.kobodir, u"kepub", volumeid)
+        return os.path.join(self.kobodir, "kepub", volumeid)
 
     def __getmacaddrs (self):
         """The list of all MAC addresses on this machine."""
@@ -454,7 +454,7 @@ class KoboLibrary(object):
             output = subprocess.check_output('/sbin/ifconfig -a', shell=True)
             matches = c.findall(output)
             for m in matches:
-                # print u"m:{0}".format(m[0])
+                # print "m:{0}".format(m[0])
                 macaddrs.append(m[0].upper())
         else:
             # probably linux
@@ -607,32 +607,32 @@ class KoboFile(object):
             # assume utf-8 with no BOM
             textoffset = 0
             stride = 1
-            print(u"Checking text:{0}:".format(contents[:10]))
+            print("Checking text:{0}:".format(contents[:10]))
             # check for byte order mark
             if contents[:3]==b"\xef\xbb\xbf":
                 # seems to be utf-8 with BOM
-                print(u"Could be utf-8 with BOM")
+                print("Could be utf-8 with BOM")
                 textoffset = 3
             elif contents[:2]==b"\xfe\xff":
                 # seems to be utf-16BE
-                print(u"Could be  utf-16BE")
+                print("Could be  utf-16BE")
                 textoffset = 3
                 stride = 2
             elif contents[:2]==b"\xff\xfe":
                 # seems to be utf-16LE
-                print(u"Could be  utf-16LE")
+                print("Could be  utf-16LE")
                 textoffset = 2
                 stride = 2
             else:
-                print(u"Perhaps utf-8 without BOM")
+                print("Perhaps utf-8 without BOM")
 
             # now check that the first few characters are in the ASCII range
             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,contents[i]))
+                    print("Bad character at {0}, value {1}".format(i,contents[i]))
                     raise ValueError
-            print(u"Seems to be good text")
+            print("Seems to be good text")
             return True
             if contents[:5]==b"<?xml" or contents[:8]==b"\xef\xbb\xbf<?xml":
                 # utf-8
@@ -653,13 +653,13 @@ class KoboFile(object):
                 # utf-16LE of weird <!DOCTYPE start
                 return True
             else:
-                print(u"Bad XML: {0}".format(contents[:8]))
+                print("Bad XML: {0}".format(contents[:8]))
                 raise ValueError
         elif self.mimetype == 'image/jpeg':
             if contents[:3] == b'\xff\xd8\xff':
                 return True
             else:
-                print(u"Bad JPEG: {0}".format(contents[:3].hex()))
+                print("Bad JPEG: {0}".format(contents[:3].hex()))
                 raise ValueError()
         return False
 
@@ -682,18 +682,18 @@ class KoboFile(object):
         return contents
 
 def decrypt_book(book, lib):
-    print(u"Converting {0}".format(book.title))
+    print("Converting {0}".format(book.title))
     zin = zipfile.ZipFile(book.filename, "r")
     # make filename out of Unicode alphanumeric and whitespace equivalents from title
-    outname = u"{0}.epub".format(re.sub('[^\s\w]', '_', book.title, 0, re.UNICODE))
+    outname = "{0}.epub".format(re.sub('[^\s\w]', '_', book.title, 0, re.UNICODE))
     if (book.type == 'drm-free'):
-        print(u"DRM-free book, conversion is not needed")
+        print("DRM-free book, conversion is not needed")
         shutil.copyfile(book.filename, outname)
-        print(u"Book saved as {0}".format(os.path.join(os.getcwd(), outname)))
+        print("Book saved as {0}".format(os.path.join(os.getcwd(), outname)))
         return 0
     result = 1
     for userkey in lib.userkeys:
-        print(u"Trying key: {0}".format(userkey.hex()))
+        print("Trying key: {0}".format(userkey.hex()))
         try:
             zout = zipfile.ZipFile(outname, "w", zipfile.ZIP_DEFLATED)
             for filename in zin.namelist():
@@ -705,12 +705,12 @@ def decrypt_book(book, lib):
                     file.check(contents)
                 zout.writestr(filename, contents)
             zout.close()
-            print(u"Decryption succeeded.")
-            print(u"Book saved as {0}".format(os.path.join(os.getcwd(), outname)))
+            print("Decryption succeeded.")
+            print("Book saved as {0}".format(os.path.join(os.getcwd(), outname)))
             result = 0
             break
         except ValueError:
-            print(u"Decryption failed.")
+            print("Decryption failed.")
             zout.close()
             os.remove(outname)
     zin.close()
@@ -719,7 +719,7 @@ def decrypt_book(book, lib):
 
 def cli_main():
     description = __about__
-    epilog = u"Parsing of arguments failed."
+    epilog = "Parsing of arguments failed."
     parser = argparse.ArgumentParser(prog=sys.argv[0], description=description, epilog=epilog)
     parser.add_argument('--devicedir', default='/media/KOBOeReader', help="directory of connected Kobo device")
     parser.add_argument('--all', action='store_true', help="flag for converting all books on device")
@@ -735,25 +735,25 @@ def cli_main():
         books = lib.books
     else:
         for i, book in enumerate(lib.books):
-            print(u"{0}: {1}".format(i + 1, book.title))
-        print(u"Or 'all'")
+            print("{0}: {1}".format(i + 1, book.title))
+        print("Or 'all'")
 
-        choice = input(u"Convert book number... ")
-        if choice == u'all':
+        choice = input("Convert book number... ")
+        if choice == "all":
             books = list(lib.books)
         else:
             try:
                 num = int(choice)
                 books = [lib.books[num - 1]]
             except (ValueError, IndexError):
-                print(u"Invalid choice. Exiting...")
+                print("Invalid choice. Exiting...")
                 exit()
 
     results = [decrypt_book(book, lib) for book in books]
     lib.close()
     overall_result = all(result != 0 for result in results)
     if overall_result != 0:
-        print(u"Could not decrypt book with any of the keys found.")
+        print("Could not decrypt book with any of the keys found.")
     return overall_result
 
 
diff --git a/Obok_plugin/utilities.py b/Obok_plugin/utilities.py
index f81bd1c..b2f02ad 100644
--- a/Obok_plugin/utilities.py
+++ b/Obok_plugin/utilities.py
@@ -1,6 +1,6 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import (unicode_literals, division, absolute_import,
-                        print_function)
 
 __license__   = 'GPL v3'
 __docformat__ = 'restructuredtext en'
@@ -13,10 +13,7 @@ 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 PyQt5.Qt import (Qt, QDialog, QPixmap, QIcon, QLabel, QHBoxLayout, QFont, QTableWidgetItem)
 
 from calibre.utils.config import config_dir
 from calibre.constants import iswindows, DEBUG