py3: more work toward universal __future__s

src/calibre/gui2/__init__.py

@@ -1,6 +1,10 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
+
 """ The GUI """
+
 import glob
 import os
 import signal
@@ -354,7 +358,7 @@ def is_widescreen():
     global _is_widescreen
     if _is_widescreen is None:
         try:
-            _is_widescreen = float(available_width())/available_height() > 1.4
+            _is_widescreen = available_width()/available_height() > 1.4
         except:
             _is_widescreen = False
     return _is_widescreen
@@ -736,7 +740,7 @@ class Translator(QTranslator):
         try:
             src = unicode_type(args[1])
         except:
-            return u''
+            return ''
         t = _
         return t(src)
 
@@ -766,8 +770,8 @@ def load_builtin_fonts():
                 if fid > -1:
                     fam = QFontDatabase.applicationFontFamilies(fid)
                     fam = set(map(unicode_type, fam))
-                    if u'calibre Symbols' in fam:
+                    if 'calibre Symbols' in fam:
-                        _rating_font = u'calibre Symbols'
+                        _rating_font = 'calibre Symbols'
 
 
 def setup_gui_option_parser(parser):
@@ -881,7 +885,7 @@ class Application(QApplication):
         self.line_height = max(12, QFontMetrics(self.font()).lineSpacing())
 
         dl = QLocale(get_lang())
-        if unicode_type(dl.bcp47Name()) != u'C':
+        if unicode_type(dl.bcp47Name()) != 'C':
             QLocale.setDefault(dl)
         global gui_thread, qt_app
         gui_thread = QThread.currentThread()
@@ -978,22 +982,22 @@ class Application(QApplication):
         icon_map = self.__icon_map_memory_ = {}
         pcache = {}
         for k, v in iteritems({
-            'DialogYesButton': u'ok.png',
+            'DialogYesButton': 'ok.png',
-            'DialogNoButton': u'window-close.png',
+            'DialogNoButton': 'window-close.png',
-            'DialogCloseButton': u'window-close.png',
+            'DialogCloseButton': 'window-close.png',
-            'DialogOkButton': u'ok.png',
+            'DialogOkButton': 'ok.png',
-            'DialogCancelButton': u'window-close.png',
+            'DialogCancelButton': 'window-close.png',
-            'DialogHelpButton': u'help.png',
+            'DialogHelpButton': 'help.png',
-            'DialogOpenButton': u'document_open.png',
+            'DialogOpenButton': 'document_open.png',
-            'DialogSaveButton': u'save.png',
+            'DialogSaveButton': 'save.png',
-            'DialogApplyButton': u'ok.png',
+            'DialogApplyButton': 'ok.png',
-            'DialogDiscardButton': u'trash.png',
+            'DialogDiscardButton': 'trash.png',
-            'MessageBoxInformation': u'dialog_information.png',
+            'MessageBoxInformation': 'dialog_information.png',
-            'MessageBoxWarning': u'dialog_warning.png',
+            'MessageBoxWarning': 'dialog_warning.png',
-            'MessageBoxCritical': u'dialog_error.png',
+            'MessageBoxCritical': 'dialog_error.png',
-            'MessageBoxQuestion': u'dialog_question.png',
+            'MessageBoxQuestion': 'dialog_question.png',
-            'BrowserReload': u'view-refresh.png',
+            'BrowserReload': 'view-refresh.png',
-            'LineEditClearButton': u'clear_left.png',
+            'LineEditClearButton': 'clear_left.png',
         }):
             if v not in pcache:
                 p = I(v)
@@ -1242,7 +1246,7 @@ def elided_text(text, font=None, width=300, pos='middle'):
     from PyQt5.Qt import QFontMetrics, QApplication
     fm = QApplication.fontMetrics() if font is None else (font if isinstance(font, QFontMetrics) else QFontMetrics(font))
     delta = 4
-    ellipsis = u'\u2026'
+    ellipsis = '\u2026'
 
     def remove_middle(x):
         mid = len(x) // 2
@@ -1361,7 +1365,7 @@ def set_app_uid(val):
     try:
         AppUserModelID(unicode_type(val))
     except Exception as err:
-        prints(u'Failed to set app uid with error:', as_unicode(err))
+        prints('Failed to set app uid with error:', as_unicode(err))
         return False
     return True
 

src/calibre/gui2/actions/__init__.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -19,7 +20,7 @@ from polyglot.builtins import unicode_type, string_or_bytes
 
 
 def menu_action_unique_name(plugin, unique_name):
-    return u'%s : menu action : %s'%(plugin.unique_name, unique_name)
+    return '%s : menu action : %s'%(plugin.unique_name, unique_name)
 
 
 class InterfaceAction(QObject):
@@ -151,7 +152,7 @@ class InterfaceAction(QObject):
         bn = self.__class__.__name__
         if getattr(self.interface_action_base_plugin, 'name'):
             bn = self.interface_action_base_plugin.name
-        return u'Interface Action: %s (%s)'%(bn, self.name)
+        return 'Interface Action: %s (%s)'%(bn, self.name)
 
     def create_action(self, spec=None, attr='qaction', shortcut_name=None):
         if spec is None:

src/calibre/gui2/actions/add.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/add_to_library.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/annotate.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/catalog.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/choose_library.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
-from __future__ import print_function
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
@@ -252,7 +252,7 @@ class ChooseLibraryAction(InterfaceAction):
         for i in range(5):
             ac = self.create_action(spec=('', None, None, None),
                     attr='switch_action%d'%i)
-            ac.setObjectName(str(i))
+            ac.setObjectName(unicode_type(i))
             self.switch_actions.append(ac)
             ac.setVisible(False)
             connect_lambda(ac.triggered, self, lambda self:
@@ -329,7 +329,7 @@ class ChooseLibraryAction(InterfaceAction):
             self.prev_lname = self.last_lname
             self.last_lname = lname
         if len(lname) > 16:
-            lname = lname[:16] + u'…'
+            lname = lname[:16] + '…'
         a = self.qaction
         a.setText(lname.replace('&', '&&&'))  # I have no idea why this requires a triple ampersand
         self.update_tooltip(db.count())

src/calibre/gui2/actions/convert.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/copy_to_library.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/delete.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/device.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/edit_collections.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/edit_metadata.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -648,7 +649,7 @@ class EditMetadataAction(InterfaceAction):
                 if not dest_mi.comments:
                     dest_mi.comments = src_mi.comments
                 else:
-                    dest_mi.comments = unicode_type(dest_mi.comments) + u'\n\n' + unicode_type(src_mi.comments)
+                    dest_mi.comments = unicode_type(dest_mi.comments) + '\n\n' + unicode_type(src_mi.comments)
             if src_mi.title and (not dest_mi.title or dest_mi.title == _('Unknown')):
                 dest_mi.title = src_mi.title
             if (src_mi.authors and src_mi.authors[0] != _('Unknown')) and (not dest_mi.authors or dest_mi.authors[0] == _('Unknown')):
@@ -701,7 +702,7 @@ class EditMetadataAction(InterfaceAction):
                     if not dest_value:
                         db.set_custom(dest_id, src_value, num=colnum)
                     else:
-                        dest_value = unicode_type(dest_value) + u'\n\n' + unicode_type(src_value)
+                        dest_value = unicode_type(dest_value) + '\n\n' + unicode_type(src_value)
                         db.set_custom(dest_id, dest_value, num=colnum)
                 if (dt in {'bool', 'int', 'float', 'rating', 'datetime'} and dest_value is None):
                     db.set_custom(dest_id, src_value, num=colnum)

src/calibre/gui2/actions/fetch_news.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/help.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -22,6 +23,3 @@ class HelpAction(InterfaceAction):
 
     def show_help(self, *args):
         open_url(QUrl(localize_user_manual_link('https://manual.calibre-ebook.com')))
-
-
-

src/calibre/gui2/actions/next_match.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/open.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -24,5 +25,3 @@ class OpenFolderAction(InterfaceAction):
         enabled = loc == 'library'
         self.qaction.setEnabled(enabled)
         self.menuless_qaction.setEnabled(enabled)
-
-

src/calibre/gui2/actions/preferences.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/restart.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -19,5 +20,3 @@ class RestartAction(InterfaceAction):
 
     def restart(self, *args):
         self.gui.quit(restart=True)
-
-

src/calibre/gui2/actions/save_to_disk.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -7,12 +8,11 @@ __docformat__ = 'restructuredtext en'
 
 import os, numbers
 from functools import partial
-from polyglot.builtins import itervalues, map
-
 
 from calibre.utils.config import prefs
 from calibre.gui2 import error_dialog, Dispatcher, choose_dir
 from calibre.gui2.actions import InterfaceAction
+from polyglot.builtins import itervalues, map
 
 
 class SaveToDiskAction(InterfaceAction):

src/calibre/gui2/actions/show_book_details.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/show_quickview.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/show_template_tester.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/similar_books.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/tweak_epub.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/unpack_book.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/actions/view.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/catalog/catalog_bibtex.py

@@ -1,16 +1,17 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
 
+from PyQt5.Qt import QWidget, QListWidgetItem
+
 from calibre.gui2 import gprefs
 from calibre.gui2.catalog.catalog_bibtex_ui import Ui_Form
 from polyglot.builtins import unicode_type, range
-from PyQt5.Qt import QWidget, QListWidgetItem
 
 
 class PluginWidget(QWidget, Ui_Form):

src/calibre/gui2/catalog/catalog_csv_xml.py

@@ -1,15 +1,16 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
+from PyQt5.Qt import QWidget, QListWidgetItem, Qt, QVBoxLayout, QLabel, QListWidget
+
 from calibre.gui2 import gprefs
 from calibre.gui2.ui import get_gui
 from polyglot.builtins import unicode_type, range
-from PyQt5.Qt import QWidget, QListWidgetItem, Qt, QVBoxLayout, QLabel, QListWidget
 
 
 def get_saved_field_data(name, all_fields):

src/calibre/gui2/catalog/catalog_epub_mobi.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -15,7 +15,7 @@ from calibre.gui2 import gprefs, open_url, question_dialog, error_dialog
 from calibre.utils.config import JSONConfig
 from calibre.utils.icu import sort_key
 from calibre.utils.localization import localize_user_manual_link
-from polyglot.builtins import unicode_type, zip, range
+from polyglot.builtins import native_string_type, unicode_type, zip, range
 
 from .catalog_epub_mobi_ui import Ui_Form
 from PyQt5.Qt import (Qt, QAbstractItemView, QCheckBox, QComboBox,
@@ -115,7 +115,7 @@ class PluginWidget(QWidget,Ui_Form):
                                'name':_('Wishlist item'),
                                'field':_('Tags'),
                                'pattern':'Wishlist',
-                               'prefix':u'\u00d7'},],
+                               'prefix':'\u00d7'},],
                              ['table_widget','table_widget']))
 
         self.OPTION_FIELDS = option_fields
@@ -423,7 +423,7 @@ class PluginWidget(QWidget,Ui_Form):
         # Hook Preset signals
         self.preset_delete_pb.clicked.connect(self.preset_remove)
         self.preset_save_pb.clicked.connect(self.preset_save)
-        self.preset_field.currentIndexChanged[str].connect(self.preset_change)
+        self.preset_field.currentIndexChanged[native_string_type].connect(self.preset_change)
 
         self.blocking_all_signals = False
 
@@ -1338,127 +1338,127 @@ class PrefixRules(GenericRulesTable):
 
         # Create a list of prefixes for user selection
         raw_prefix_list = [
-            ('Ampersand',u'&'),
+            ('Ampersand', '&'),
-            ('Angle left double',u'\u00ab'),
+            ('Angle left double', '\u00ab'),
-            ('Angle left',u'\u2039'),
+            ('Angle left', '\u2039'),
-            ('Angle right double',u'\u00bb'),
+            ('Angle right double', '\u00bb'),
-            ('Angle right',u'\u203a'),
+            ('Angle right', '\u203a'),
-            ('Arrow carriage return',u'\u21b5'),
+            ('Arrow carriage return', '\u21b5'),
-            ('Arrow double',u'\u2194'),
+            ('Arrow double', '\u2194'),
-            ('Arrow down',u'\u2193'),
+            ('Arrow down', '\u2193'),
-            ('Arrow left',u'\u2190'),
+            ('Arrow left', '\u2190'),
-            ('Arrow right',u'\u2192'),
+            ('Arrow right', '\u2192'),
-            ('Arrow up',u'\u2191'),
+            ('Arrow up', '\u2191'),
-            ('Asterisk',u'*'),
+            ('Asterisk', '*'),
-            ('At sign',u'@'),
+            ('At sign', '@'),
-            ('Bullet smallest',u'\u22c5'),
+            ('Bullet smallest', '\u22c5'),
-            ('Bullet small',u'\u00b7'),
+            ('Bullet small', '\u00b7'),
-            ('Bullet',u'\u2022'),
+            ('Bullet', '\u2022'),
-            ('Cards clubs',u'\u2663'),
+            ('Cards clubs', '\u2663'),
-            ('Cards diamonds',u'\u2666'),
+            ('Cards diamonds', '\u2666'),
-            ('Cards hearts',u'\u2665'),
+            ('Cards hearts', '\u2665'),
-            ('Cards spades',u'\u2660'),
+            ('Cards spades', '\u2660'),
-            ('Caret',u'^'),
+            ('Caret', '^'),
-            ('Checkmark',u'\u2713'),
+            ('Checkmark', '\u2713'),
-            ('Copyright circle c',u'\u00a9'),
+            ('Copyright circle c', '\u00a9'),
-            ('Copyright circle r',u'\u00ae'),
+            ('Copyright circle r', '\u00ae'),
-            ('Copyright trademark',u'\u2122'),
+            ('Copyright trademark', '\u2122'),
-            ('Currency cent',u'\u00a2'),
+            ('Currency cent', '\u00a2'),
-            ('Currency dollar',u'$'),
+            ('Currency dollar', '$'),
-            ('Currency euro',u'\u20ac'),
+            ('Currency euro', '\u20ac'),
-            ('Currency pound',u'\u00a3'),
+            ('Currency pound', '\u00a3'),
-            ('Currency yen',u'\u00a5'),
+            ('Currency yen', '\u00a5'),
-            ('Dagger double',u'\u2021'),
+            ('Dagger double', '\u2021'),
-            ('Dagger',u'\u2020'),
+            ('Dagger', '\u2020'),
-            ('Degree',u'\u00b0'),
+            ('Degree', '\u00b0'),
-            ('Dots3',u'\u2234'),
+            ('Dots3', '\u2234'),
-            ('Hash',u'#'),
+            ('Hash', '#'),
-            ('Infinity',u'\u221e'),
+            ('Infinity', '\u221e'),
-            ('Lozenge',u'\u25ca'),
+            ('Lozenge', '\u25ca'),
-            ('Math divide',u'\u00f7'),
+            ('Math divide', '\u00f7'),
-            ('Math empty',u'\u2205'),
+            ('Math empty', '\u2205'),
-            ('Math equals',u'='),
+            ('Math equals', '='),
-            ('Math minus',u'\u2212'),
+            ('Math minus', '\u2212'),
-            ('Math plus circled',u'\u2295'),
+            ('Math plus circled', '\u2295'),
-            ('Math times circled',u'\u2297'),
+            ('Math times circled', '\u2297'),
-            ('Math times',u'\u00d7'),
+            ('Math times', '\u00d7'),
-            ('Paragraph',u'\u00b6'),
+            ('Paragraph', '\u00b6'),
-            ('Percent',u'%'),
+            ('Percent', '%'),
-            ('Plus-or-minus',u'\u00b1'),
+            ('Plus-or-minus', '\u00b1'),
-            ('Plus',u'+'),
+            ('Plus', '+'),
-            ('Punctuation colon',u':'),
+            ('Punctuation colon', ':'),
-            ('Punctuation colon-semi',u';'),
+            ('Punctuation colon-semi', ';'),
-            ('Punctuation exclamation',u'!'),
+            ('Punctuation exclamation', '!'),
-            ('Punctuation question',u'?'),
+            ('Punctuation question', '?'),
-            ('Punctuation period',u'.'),
+            ('Punctuation period', '.'),
-            ('Punctuation slash back',u'\\'),
+            ('Punctuation slash back', '\\'),
-            ('Punctuation slash forward',u'/'),
+            ('Punctuation slash forward', '/'),
-            ('Section',u'\u00a7'),
+            ('Section', '\u00a7'),
-            ('Tilde',u'~'),
+            ('Tilde', '~'),
-            ('Vertical bar',u'|'),
+            ('Vertical bar', '|'),
-            ('Vertical bar broken',u'\u00a6'),
+            ('Vertical bar broken', '\u00a6'),
-            ('_0',u'0'),
+            ('_0', '0'),
-            ('_1',u'1'),
+            ('_1', '1'),
-            ('_2',u'2'),
+            ('_2', '2'),
-            ('_3',u'3'),
+            ('_3', '3'),
-            ('_4',u'4'),
+            ('_4', '4'),
-            ('_5',u'5'),
+            ('_5', '5'),
-            ('_6',u'6'),
+            ('_6', '6'),
-            ('_7',u'7'),
+            ('_7', '7'),
-            ('_8',u'8'),
+            ('_8', '8'),
-            ('_9',u'9'),
+            ('_9', '9'),
-            ('_A',u'A'),
+            ('_A', 'A'),
-            ('_B',u'B'),
+            ('_B', 'B'),
-            ('_C',u'C'),
+            ('_C', 'C'),
-            ('_D',u'D'),
+            ('_D', 'D'),
-            ('_E',u'E'),
+            ('_E', 'E'),
-            ('_F',u'F'),
+            ('_F', 'F'),
-            ('_G',u'G'),
+            ('_G', 'G'),
-            ('_H',u'H'),
+            ('_H', 'H'),
-            ('_I',u'I'),
+            ('_I', 'I'),
-            ('_J',u'J'),
+            ('_J', 'J'),
-            ('_K',u'K'),
+            ('_K', 'K'),
-            ('_L',u'L'),
+            ('_L', 'L'),
-            ('_M',u'M'),
+            ('_M', 'M'),
-            ('_N',u'N'),
+            ('_N', 'N'),
-            ('_O',u'O'),
+            ('_O', 'O'),
-            ('_P',u'P'),
+            ('_P', 'P'),
-            ('_Q',u'Q'),
+            ('_Q', 'Q'),
-            ('_R',u'R'),
+            ('_R', 'R'),
-            ('_S',u'S'),
+            ('_S', 'S'),
-            ('_T',u'T'),
+            ('_T', 'T'),
-            ('_U',u'U'),
+            ('_U', 'U'),
-            ('_V',u'V'),
+            ('_V', 'V'),
-            ('_W',u'W'),
+            ('_W', 'W'),
-            ('_X',u'X'),
+            ('_X', 'X'),
-            ('_Y',u'Y'),
+            ('_Y', 'Y'),
-            ('_Z',u'Z'),
+            ('_Z', 'Z'),
-            ('_a',u'a'),
+            ('_a', 'a'),
-            ('_b',u'b'),
+            ('_b', 'b'),
-            ('_c',u'c'),
+            ('_c', 'c'),
-            ('_d',u'd'),
+            ('_d', 'd'),
-            ('_e',u'e'),
+            ('_e', 'e'),
-            ('_f',u'f'),
+            ('_f', 'f'),
-            ('_g',u'g'),
+            ('_g', 'g'),
-            ('_h',u'h'),
+            ('_h', 'h'),
-            ('_i',u'i'),
+            ('_i', 'i'),
-            ('_j',u'j'),
+            ('_j', 'j'),
-            ('_k',u'k'),
+            ('_k', 'k'),
-            ('_l',u'l'),
+            ('_l', 'l'),
-            ('_m',u'm'),
+            ('_m', 'm'),
-            ('_n',u'n'),
+            ('_n', 'n'),
-            ('_o',u'o'),
+            ('_o', 'o'),
-            ('_p',u'p'),
+            ('_p', 'p'),
-            ('_q',u'q'),
+            ('_q', 'q'),
-            ('_r',u'r'),
+            ('_r', 'r'),
-            ('_s',u's'),
+            ('_s', 's'),
-            ('_t',u't'),
+            ('_t', 't'),
-            ('_u',u'u'),
+            ('_u', 'u'),
-            ('_v',u'v'),
+            ('_v', 'v'),
-            ('_w',u'w'),
+            ('_w', 'w'),
-            ('_x',u'x'),
+            ('_x', 'x'),
-            ('_y',u'y'),
+            ('_y', 'y'),
-            ('_z',u'z'),
+            ('_z', 'z'),
             ]
         raw_prefix_list = sorted(raw_prefix_list, key=prefix_sorter)
         self.prefix_list = [x[1] for x in raw_prefix_list]

src/calibre/gui2/comments_editor.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -338,7 +339,7 @@ class EditorWidget(QWebView, LineEditECM):  # {{{
 
     @property
     def html(self):
-        ans = u''
+        ans = ''
         try:
             if not self.page().mainFrame().documentElement().findFirst('meta[name="calibre-dont-sanitize"]').isNull():
                 # Bypass cleanup if special meta tag exists
@@ -364,9 +365,9 @@ class EditorWidget(QWebView, LineEditECM):  # {{{
                     x.tag not in ('script', 'style')]
 
             if len(elems) > 1:
-                ans = u'<div>%s</div>'%(u''.join(elems))
+                ans = '<div>%s</div>'%(''.join(elems))
             else:
-                ans = u''.join(elems)
+                ans = ''.join(elems)
                 if not ans.startswith('<'):
                     ans = '<p>%s</p>'%ans
             ans = xml_replace_entities(ans)
@@ -482,7 +483,7 @@ class Highlighter(QSyntaxHighlighter):
             if state == State_Comment:
                 start = pos
                 while pos < len_:
-                    if text[pos:pos+3] == u"-->":
+                    if text[pos:pos+3] == "-->":
                         pos += 3
                         state = State_Text
                         break
@@ -495,7 +496,7 @@ class Highlighter(QSyntaxHighlighter):
                 while pos < len_:
                     ch = text[pos]
                     pos += 1
-                    if ch == u'>':
+                    if ch == '>':
                         state = State_Text
                         break
                 self.setFormat(start, pos - start, self.colors['doctype'])
@@ -506,7 +507,7 @@ class Highlighter(QSyntaxHighlighter):
                 while pos < len_:
                     ch = text[pos]
                     pos += 1
-                    if ch == u'>':
+                    if ch == '>':
                         state = State_Text
                         break
                     if not ch.isspace():
@@ -524,7 +525,7 @@ class Highlighter(QSyntaxHighlighter):
                         pos -= 1
                         state = State_InsideTag
                         break
-                    if ch == u'>':
+                    if ch == '>':
                         state = State_Text
                         break
                 self.setFormat(start, pos - start, self.colors['tag'])
@@ -537,10 +538,10 @@ class Highlighter(QSyntaxHighlighter):
                     ch = text[pos]
                     pos += 1
 
-                    if ch == u'/':
+                    if ch == '/':
                         continue
 
-                    if ch == u'>':
+                    if ch == '>':
                         state = State_Text
                         break
 
@@ -557,11 +558,11 @@ class Highlighter(QSyntaxHighlighter):
                     ch = text[pos]
                     pos += 1
 
-                    if ch == u'=':
+                    if ch == '=':
                         state = State_AttributeValue
                         break
 
-                    if ch in (u'>', u'/'):
+                    if ch in ('>', '/'):
                         state = State_InsideTag
                         break
 
@@ -577,12 +578,12 @@ class Highlighter(QSyntaxHighlighter):
                     pos += 1
 
                     # handle opening single quote
-                    if ch == u"'":
+                    if ch == "'":
                         state = State_SingleQuote
                         break
 
                     # handle opening double quote
-                    if ch == u'"':
+                    if ch == '"':
                         state = State_DoubleQuote
                         break
 
@@ -597,7 +598,7 @@ class Highlighter(QSyntaxHighlighter):
                         ch = text[pos]
                         if ch.isspace():
                             break
-                        if ch in (u'>', u'/'):
+                        if ch in ('>', '/'):
                             break
                         pos += 1
                     state = State_InsideTag
@@ -610,7 +611,7 @@ class Highlighter(QSyntaxHighlighter):
                 while pos < len_:
                     ch = text[pos]
                     pos += 1
-                    if ch == u"'":
+                    if ch == "'":
                         break
 
                 state = State_InsideTag
@@ -624,7 +625,7 @@ class Highlighter(QSyntaxHighlighter):
                 while pos < len_:
                     ch = text[pos]
                     pos += 1
-                    if ch == u'"':
+                    if ch == '"':
                         break
 
                 state = State_InsideTag
@@ -635,18 +636,18 @@ class Highlighter(QSyntaxHighlighter):
                 # State_Text and default
                 while pos < len_:
                     ch = text[pos]
-                    if ch == u'<':
+                    if ch == '<':
-                        if text[pos:pos+4] == u"<!--":
+                        if text[pos:pos+4] == "<!--":
                             state = State_Comment
                         else:
-                            if text[pos:pos+9].upper() == u"<!DOCTYPE":
+                            if text[pos:pos+9].upper() == "<!DOCTYPE":
                                 state = State_DocType
                             else:
                                 state = State_TagStart
                         break
-                    elif ch == u'&':
+                    elif ch == '&':
                         start = pos
-                        while pos < len_ and text[pos] != u';':
+                        while pos < len_ and text[pos] != ';':
                             self.setFormat(start, pos - start,
                                     self.colors['entity'])
                             pos += 1

src/calibre/gui2/convert/azw3_output.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/convert/comic_input.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/convert/docx_output.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'

src/calibre/gui2/convert/epub_output.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/convert/fb2_input.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'

src/calibre/gui2/convert/fb2_output.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'

src/calibre/gui2/convert/htmlz_output.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'

src/calibre/gui2/convert/lrf_output.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/convert/mobi_output.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'

src/calibre/gui2/convert/pdb_output.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'

src/calibre/gui2/convert/txtz_output.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__ = 'GPL 3'
 __copyright__ = '2011, John Schember <john@nachtimwald.com>'

src/calibre/gui2/device.py

@@ -1,4 +1,5 @@
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 
@@ -34,7 +35,7 @@ from calibre.utils.config import tweaks, device_prefs
 from calibre.utils.img import scale_image
 from calibre.library.save_to_disk import find_plugboard
 from calibre.ptempfile import PersistentTemporaryFile, force_unicode as filename_to_unicode
-from polyglot.builtins import unicode_type, string_or_bytes
+from polyglot.builtins import unicode_type, string_or_unicode
 from polyglot import queue
 # }}}
 
@@ -209,7 +210,7 @@ class DeviceManager(Thread):  # {{{
                 tb = traceback.format_exc()
                 if DEBUG or tb not in self.reported_errors:
                     self.reported_errors.add(tb)
-                    prints('Unable to open device', str(dev))
+                    prints('Unable to open device', unicode_type(dev))
                     prints(tb)
                 continue
             self.after_device_connect(dev, device_kind)
@@ -472,7 +473,7 @@ class DeviceManager(Thread):  # {{{
         info = self.device.get_device_information(end_session=False)
         if len(info) < 5:
             info = tuple(list(info) + [{}])
-        info = [i.replace('\x00', '').replace('\x01', '') if isinstance(i, string_or_bytes) else i
+        info = [i.replace('\x00', '').replace('\x01', '') if isinstance(i, string_or_unicode) else i
                  for i in info]
         cp = self.device.card_prefix(end_session=False)
         fs = self.device.free_space()
@@ -604,7 +605,7 @@ class DeviceManager(Thread):  # {{{
                      metadata=None, plugboards=None, add_as_step_to_job=None):
         desc = ngettext('Upload one book to the device', 'Upload {} books to the device', len(names)).format(len(names))
         if titles:
-            desc += u': ' + u', '.join(titles)
+            desc += ': ' + ', '.join(titles)
         return self.create_job_step(self._upload_books, done, to_job=add_as_step_to_job,
                                args=[files, names],
                 kwargs={'on_card':on_card,'metadata':metadata,'plugboards':plugboards}, description=desc)
@@ -930,7 +931,7 @@ class DeviceMixin(object):  # {{{
         d.show()
 
     def auto_convert_question(self, msg, autos):
-        autos = u'\n'.join(map(unicode_type, map(force_unicode, autos)))
+        autos = '\n'.join(map(unicode_type, map(force_unicode, autos)))
         return self.ask_a_yes_no_question(
                 _('No suitable formats'), msg,
                 ans_when_user_unavailable=True,
@@ -1627,7 +1628,7 @@ class DeviceMixin(object):  # {{{
 
         if job.exception is not None:
             if isinstance(job.exception, FreeSpaceError):
-                where = 'in main memory.' if 'memory' in str(job.exception) \
+                where = 'in main memory.' if 'memory' in unicode_type(job.exception) \
                         else 'on the storage card.'
                 titles = '\n'.join(['<li>'+mi.title+'</li>'
                                     for mi in metadata])

src/calibre/gui2/notify.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -44,7 +44,7 @@ class DBUSNotifier(Notifier):
             self._notify = dbus.Interface(session_bus.get_object(server, path), interface)
         except Exception as err:
             self.ok = False
-            self.err = str(err)
+            self.err = unicode_type(err)
         if DEBUG:
             prints(server, 'found' if self.ok else 'not found', 'in', '%.1f' % (time.time() - start), 'seconds')
 

src/calibre/gui2/search_box.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python2
 # vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import with_statement
+from __future__ import absolute_import, division, print_function, unicode_literals
 
 __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
@@ -20,7 +20,7 @@ from calibre.gui2.dialogs.confirm_delete import confirm
 from calibre.gui2.dialogs.saved_search_editor import SavedSearchEditor
 from calibre.gui2.dialogs.search import SearchDialog
 from calibre.utils.icu import primary_sort_key
-from polyglot.builtins import unicode_type, string_or_bytes, map, range
+from polyglot.builtins import native_string_type, unicode_type, string_or_bytes, map, range
 
 QT_HIDDEN_CLEAR_ACTION = '_q_qlineeditclearaction'
 
@@ -119,11 +119,11 @@ class SearchBox2(QComboBox):  # {{{
 
         c = self.line_edit.completer()
         c.setCompletionMode(c.PopupCompletion)
-        c.highlighted[str].connect(self.completer_used)
+        c.highlighted[native_string_type].connect(self.completer_used)
 
         self.line_edit.key_pressed.connect(self.key_pressed, type=Qt.DirectConnection)
         # QueuedConnection as workaround for https://bugreports.qt-project.org/browse/QTBUG-40807
-        self.activated[str].connect(self.history_selected, type=Qt.QueuedConnection)
+        self.activated[native_string_type].connect(self.history_selected, type=Qt.QueuedConnection)
         self.setEditable(True)
         self.as_you_type = True
         self.timer = QTimer()
@@ -272,7 +272,7 @@ class SearchBox2(QComboBox):  # {{{
 
     def set_search_string(self, txt, store_in_history=False, emit_changed=True):
         if not store_in_history:
-            self.activated[str].disconnect()
+            self.activated[native_string_type].disconnect()
         try:
             self.setFocus(Qt.OtherFocusReason)
             if not txt:

src/calibre/gui2/tools.py

@@ -1,4 +1,6 @@
 #!/usr/bin/env  python2
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'

src/calibre/gui2/widgets.py

@@ -1,4 +1,5 @@
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function, unicode_literals
+
 __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 '''
@@ -23,7 +24,7 @@ from calibre.gui2.progress_indicator import ProgressIndicator as _ProgressIndica
 from calibre.gui2.dnd import (dnd_has_image, dnd_get_image, dnd_get_files,
     image_extensions, dnd_has_extension, DownloadDialog)
 from calibre.utils.localization import localize_user_manual_link
-from polyglot.builtins import unicode_type, range
+from polyglot.builtins import native_string_type, unicode_type, range
 
 history = XMLConfig('history')
 
@@ -45,11 +46,11 @@ class ProgressIndicator(QWidget):  # {{{
         pwidth, pheight = view.size().width(), view.size().height()
         self.resize(pwidth, min(pheight, 250))
         if self.pos is None:
-            self.move(0, (pheight-self.size().height())/2.)
+            self.move(0, (pheight-self.size().height())/2)
         else:
             self.move(self.pos[0], self.pos[1])
         self.pi.resize(self.pi.sizeHint())
-        self.pi.move(int((self.size().width()-self.pi.size().width())/2.), 0)
+        self.pi.move(int((self.size().width()-self.pi.size().width())//2), 0)
         self.status.resize(self.size().width(), self.size().height()-self.pi.size().height()-10)
         self.status.move(0, self.pi.size().height()+10)
         self.status.setText('<h1>'+msg+'</h1>')
@@ -137,7 +138,7 @@ class FilenamePattern(QWidget, Ui_Form):  # {{{
             self.series.setText(_('No match'))
 
         if mi.series_index is not None:
-            self.series_index.setText(str(mi.series_index))
+            self.series_index.setText(unicode_type(mi.series_index))
         else:
             self.series_index.setText(_('No match'))
 
@@ -151,7 +152,7 @@ class FilenamePattern(QWidget, Ui_Form):  # {{{
         else:
             self.pubdate.setText(_('No match'))
 
-        self.isbn.setText(_('No match') if mi.isbn is None else str(mi.isbn))
+        self.isbn.setText(_('No match') if mi.isbn is None else unicode_type(mi.isbn))
         self.comments.setText(mi.comments if mi.comments else _('No match'))
 
     def pattern(self):
@@ -304,7 +305,7 @@ def draw_size(p, rect, w, h):
     f = p.font()
     f.setBold(True)
     p.setFont(f)
-    sz = u'\u00a0%d x %d\u00a0'%(w, h)
+    sz = '\u00a0%d x %d\u00a0'%(w, h)
     flags = Qt.AlignBottom|Qt.AlignRight|Qt.TextSingleLine
     szrect = p.boundingRect(rect, flags, sz)
     p.fillRect(szrect.adjusted(0, 0, 0, 4), QColor(0, 0, 0, 200))
@@ -369,8 +370,8 @@ class ImageView(QWidget, ImageDropMixin):
             pmap = pmap.scaled(int(nw*pmap.devicePixelRatio()), int(nh*pmap.devicePixelRatio()), Qt.IgnoreAspectRatio,
                     Qt.SmoothTransformation)
         w, h = int(pmap.width()/pmap.devicePixelRatio()), int(pmap.height()/pmap.devicePixelRatio())
-        x = int(abs(cw - w)/2.)
+        x = int(abs(cw - w)//2)
-        y = int(abs(ch - h)/2.)
+        y = int(abs(ch - h)//2)
         target = QRect(x, y, w, h)
         p = QPainter(self)
         p.setRenderHints(QPainter.Antialiasing | QPainter.SmoothPixmapTransform)
@@ -570,7 +571,7 @@ class CompleteLineEdit(EnLineEdit):  # {{{
         self.completer = ItemsCompleter(self, complete_items)
         self.completer.setCaseSensitivity(Qt.CaseInsensitive)
 
-        self.completer.activated[str].connect(self.complete_text)
+        self.completer.activated[native_string_type].connect(self.complete_text)
 
         self.completer.setWidget(self)
 
@@ -888,13 +889,13 @@ class PythonHighlighter(QSyntaxHighlighter):  # {{{
         self.setFormat(0, textLength,
                        PythonHighlighter.Formats["normal"])
 
-        if text.startswith(u"Traceback") or text.startswith(u"Error: "):
+        if text.startswith("Traceback") or text.startswith("Error: "):
             self.setCurrentBlockState(ERROR)
             self.setFormat(0, textLength,
                            PythonHighlighter.Formats["error"])
             return
         if prevState == ERROR and \
-           not (text.startswith(u'>>>') or text.startswith(u"#")):
+           not (text.startswith('>>>') or text.startswith("#")):
             self.setCurrentBlockState(ERROR)
             self.setFormat(0, textLength,
                            PythonHighlighter.Formats["error"])
@@ -913,18 +914,18 @@ class PythonHighlighter(QSyntaxHighlighter):  # {{{
         # PythonHighlighter.Rules.append((QRegExp(r"#.*"), "comment"))
         if not text:
             pass
-        elif text[0] == u"#":
+        elif text[0] == "#":
             self.setFormat(0, len(text),
                            PythonHighlighter.Formats["comment"])
         else:
             stack = []
             for i, c in enumerate(text):
-                if c in (u'"', u"'"):
+                if c in ('"', "'"):
                     if stack and stack[-1] == c:
                         stack.pop()
                     else:
                         stack.append(c)
-                elif c == u"#" and len(stack) == 0:
+                elif c == "#" and len(stack) == 0:
                     self.setFormat(i, len(text),
                                    PythonHighlighter.Formats["comment"])
                     break