diff --git a/src/calibre/gui2/viewer/bookmarks.py b/src/calibre/gui2/viewer/bookmarks.py
index 73e988a359..bc918ada01 100644
--- a/src/calibre/gui2/viewer/bookmarks.py
+++ b/src/calibre/gui2/viewer/bookmarks.py
@@ -7,7 +7,7 @@ from operator import itemgetter
 from qt.core import (
     QAbstractItemView, QAction, QComboBox, QGridLayout, QHBoxLayout, QIcon,
     QInputDialog, QItemSelectionModel, QLabel, QListWidget, QListWidgetItem,
-    QPushButton, Qt, QWidget, pyqtSignal
+    QPushButton, Qt, QWidget, pyqtSignal,
 )
 
 from calibre.gui2 import choose_files, choose_save_file
@@ -17,6 +17,7 @@ from calibre.gui2.viewer.shortcuts import get_shortcut_for
 from calibre.gui2.viewer.web_view import vprefs
 from calibre.utils.date import EPOCH, utcnow
 from calibre.utils.icu import primary_sort_key
+from calibre.utils.localization import _
 
 
 class BookmarksList(QListWidget):
diff --git a/src/calibre/gui2/viewer/highlights.py b/src/calibre/gui2/viewer/highlights.py
index e652764857..18ba4a4721 100644
--- a/src/calibre/gui2/viewer/highlights.py
+++ b/src/calibre/gui2/viewer/highlights.py
@@ -28,7 +28,7 @@ from calibre.gui2.viewer.config import vprefs
 from calibre.gui2.viewer.search import SearchInput
 from calibre.gui2.viewer.shortcuts import get_shortcut_for, index_to_key_sequence
 from calibre.gui2.widgets2 import Dialog
-from calibre.utils.localization import ngettext
+from calibre.utils.localization import _, ngettext
 from calibre_extensions.progress_indicator import set_no_activate_on_click
 
 decoration_cache = {}
diff --git a/src/calibre/gui2/viewer/lookup.py b/src/calibre/gui2/viewer/lookup.py
index f1e74c1584..1dff97ae92 100644
--- a/src/calibre/gui2/viewer/lookup.py
+++ b/src/calibre/gui2/viewer/lookup.py
@@ -18,7 +18,7 @@ from calibre import prints, random_user_agent
 from calibre.gui2 import error_dialog
 from calibre.gui2.viewer.web_view import apply_font_settings, vprefs
 from calibre.gui2.widgets2 import Dialog
-from calibre.utils.localization import canonicalize_lang, get_lang, lang_as_iso639_1
+from calibre.utils.localization import _, canonicalize_lang, get_lang, lang_as_iso639_1
 from calibre.utils.resources import get_path as P
 from calibre.utils.webengine import (
     create_script, insert_scripts, secure_webengine, setup_profile,
diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index 3a9dcb45f4..3cdd57c850 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -16,6 +16,7 @@ from calibre.gui2.viewer.ui import EbookViewer, is_float
 from calibre.ptempfile import reset_base_dir
 from calibre.utils.config import JSONConfig
 from calibre.utils.ipc import viewer_socket_address
+from calibre.utils.localization import _
 
 singleinstance_name = 'calibre_viewer'
 
@@ -168,6 +169,7 @@ def run_gui(app, opts, args, internal_book_data, listener=None):
 
 def main(args=sys.argv):
     from calibre.utils.webengine import setup_fake_protocol
+
     # Ensure viewer can continue to function if GUI is closed
     os.environ.pop('CALIBRE_WORKER_TEMP_DIR', None)
     reset_base_dir()
diff --git a/src/calibre/gui2/viewer/printing.py b/src/calibre/gui2/viewer/printing.py
index 7dfe76f58b..65d3c5860b 100644
--- a/src/calibre/gui2/viewer/printing.py
+++ b/src/calibre/gui2/viewer/printing.py
@@ -5,18 +5,16 @@
 import os
 import subprocess
 import sys
-from threading import Thread
-
 from qt.core import (
-    QCheckBox, QDoubleSpinBox, QFormLayout, QHBoxLayout, QIcon, QLabel, QDialog,
-    QLineEdit, QPageSize, QProgressDialog, QTimer, QToolButton, QVBoxLayout
+    QCheckBox, QDialog, QDoubleSpinBox, QFormLayout, QHBoxLayout, QIcon, QLabel,
+    QLineEdit, QPageSize, QProgressDialog, QTimer, QToolButton, QVBoxLayout,
 )
+from threading import Thread
 
 from calibre import sanitize_file_name
 from calibre.ebooks.conversion.plugins.pdf_output import PAPER_SIZES
 from calibre.gui2 import (
-    Application, choose_save_file, dynamic, elided_text, error_dialog,
-    open_local_file
+    Application, choose_save_file, dynamic, elided_text, error_dialog, open_local_file,
 )
 from calibre.gui2.widgets import PaperSizes
 from calibre.gui2.widgets2 import Dialog
@@ -24,9 +22,9 @@ from calibre.ptempfile import PersistentTemporaryFile
 from calibre.utils.config import JSONConfig
 from calibre.utils.filenames import expanduser
 from calibre.utils.ipc.simple_worker import start_pipe_worker
+from calibre.utils.localization import _
 from calibre.utils.serialize import msgpack_dumps, msgpack_loads
 
-
 vprefs = JSONConfig('viewer')
 
 
diff --git a/src/calibre/gui2/viewer/search.py b/src/calibre/gui2/viewer/search.py
index b59118b3ea..ad43b3ec8e 100644
--- a/src/calibre/gui2/viewer/search.py
+++ b/src/calibre/gui2/viewer/search.py
@@ -19,7 +19,7 @@ from calibre.gui2.viewer.config import vprefs
 from calibre.gui2.viewer.web_view import get_data, get_manifest
 from calibre.gui2.viewer.widgets import ResultsDelegate, SearchBox
 from calibre.utils.icu import primary_collator_without_punctuation
-from calibre.utils.localization import ngettext
+from calibre.utils.localization import _, ngettext
 from polyglot.builtins import iteritems
 from polyglot.functools import lru_cache
 from polyglot.queue import Queue
diff --git a/src/calibre/gui2/viewer/toc.py b/src/calibre/gui2/viewer/toc.py
index a0447c2a6a..e105464e07 100644
--- a/src/calibre/gui2/viewer/toc.py
+++ b/src/calibre/gui2/viewer/toc.py
@@ -6,14 +6,15 @@ import re
 from functools import partial
 from qt.core import (
     QAbstractItemView, QApplication, QEvent, QFont, QHBoxLayout, QIcon, QMenu,
-    QModelIndex, QStandardItem, QStandardItemModel, QStyledItemDelegate,
-    Qt, QToolButton, QToolTip, QTreeView, QWidget, pyqtSignal
+    QModelIndex, QStandardItem, QStandardItemModel, QStyledItemDelegate, Qt,
+    QToolButton, QToolTip, QTreeView, QWidget, pyqtSignal,
 )
 
 from calibre.gui2 import error_dialog
-from calibre.gui2.search_box import SearchBox2
 from calibre.gui2.gestures import GestureManager
+from calibre.gui2.search_box import SearchBox2
 from calibre.utils.icu import primary_contains
+from calibre.utils.localization import _
 
 
 class Delegate(QStyledItemDelegate):
diff --git a/src/calibre/gui2/viewer/toolbars.py b/src/calibre/gui2/viewer/toolbars.py
index aaa245b756..2d95566cdc 100644
--- a/src/calibre/gui2/viewer/toolbars.py
+++ b/src/calibre/gui2/viewer/toolbars.py
@@ -19,6 +19,7 @@ from calibre.gui2.viewer.web_view import set_book_path, vprefs
 from calibre.gui2.widgets2 import Dialog
 from calibre.startup import connect_lambda
 from calibre.utils.icu import primary_sort_key
+from calibre.utils.localization import _
 
 
 class Action:
diff --git a/src/calibre/gui2/viewer/tts.py b/src/calibre/gui2/viewer/tts.py
index 7354b9428f..3e2f77ddb2 100644
--- a/src/calibre/gui2/viewer/tts.py
+++ b/src/calibre/gui2/viewer/tts.py
@@ -6,6 +6,7 @@ from qt.core import QDialog, QDialogButtonBox, QObject, QVBoxLayout, pyqtSignal
 from calibre.gui2 import error_dialog
 from calibre.gui2.viewer.config import get_pref_group, vprefs
 from calibre.gui2.widgets2 import Dialog
+from calibre.utils.localization import _
 
 
 def set_sync_override(allowed):
diff --git a/src/calibre/gui2/viewer/ui.py b/src/calibre/gui2/viewer/ui.py
index 2cebb9d851..b9e6813d04 100644
--- a/src/calibre/gui2/viewer/ui.py
+++ b/src/calibre/gui2/viewer/ui.py
@@ -48,6 +48,7 @@ from calibre.startup import connect_lambda
 from calibre.utils.date import utcnow
 from calibre.utils.img import image_from_path
 from calibre.utils.ipc.simple_worker import WorkerError
+from calibre.utils.localization import _
 from polyglot.builtins import as_bytes, as_unicode, iteritems, itervalues
 
 
diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index 40470c3ec0..fc077f1ea5 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 # License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
 
-
 import os
 import shutil
 import sys
@@ -28,7 +27,7 @@ from calibre.gui2.viewer.config import viewer_config_dir, vprefs
 from calibre.gui2.viewer.tts import TTS
 from calibre.gui2.webengine import RestartingWebEngineView
 from calibre.srv.code import get_translations_data
-from calibre.utils.localization import localize_user_manual_link
+from calibre.utils.localization import _, localize_user_manual_link
 from calibre.utils.resources import get_path as P
 from calibre.utils.serialize import json_loads
 from calibre.utils.shared_file import share_open
diff --git a/src/calibre/gui2/viewer/widgets.py b/src/calibre/gui2/viewer/widgets.py
index 3c2d71b80b..514fa4e20c 100644
--- a/src/calibre/gui2/viewer/widgets.py
+++ b/src/calibre/gui2/viewer/widgets.py
@@ -2,13 +2,13 @@
 # License: GPL v3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
 
 import re
-
 from qt.core import (
-    QAction, QFont, QFontMetrics, QStyle, QStyledItemDelegate, Qt, pyqtSignal, QPalette
+    QAction, QFont, QFontMetrics, QPalette, QStyle, QStyledItemDelegate, Qt, pyqtSignal,
 )
 
 from calibre.gui2 import QT_HIDDEN_CLEAR_ACTION
 from calibre.gui2.widgets2 import HistoryComboBox
+from calibre.utils.localization import _
 
 
 class ResultsDelegate(QStyledItemDelegate):  # {{{
diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index d4766439d0..da290e9832 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -25,7 +25,7 @@ from calibre.gui2.filename_pattern_ui import Ui_Form
 from calibre.gui2.progress_indicator import ProgressIndicator as _ProgressIndicator
 from calibre.startup import connect_lambda
 from calibre.utils.config import XMLConfig, prefs
-from calibre.utils.localization import localize_user_manual_link
+from calibre.utils.localization import _, localize_user_manual_link
 from polyglot.builtins import native_string_type
 
 history = XMLConfig('history')
diff --git a/src/calibre/gui2/widgets2.py b/src/calibre/gui2/widgets2.py
index 7a57ba31a2..4768b384e7 100644
--- a/src/calibre/gui2/widgets2.py
+++ b/src/calibre/gui2/widgets2.py
@@ -4,13 +4,13 @@
 
 import weakref
 from qt.core import (
-    QApplication, QBrush, QByteArray, QCalendarWidget, QCheckBox, QColor,
-    QColorDialog, QComboBox, QDate, QDateTime, QDateTimeEdit, QDialog,
-    QDialogButtonBox, QFont, QFontInfo, QFontMetrics, QFrame, QIcon, QKeySequence,
-    QLabel, QLayout, QMenu, QMimeData, QPainter, QPalette, QPixmap, QPoint,
-    QPushButton, QRect, QScrollArea, QSize, QSizePolicy, QStyle, QStyledItemDelegate,
-    QStyleOptionToolButton, QStylePainter, Qt, QTabWidget, QTextBrowser, QTextCursor,
-    QToolButton, QUndoCommand, QUndoStack, QUrl, QWidget, pyqtSignal
+    QApplication, QBrush, QByteArray, QCalendarWidget, QCheckBox, QColor, QColorDialog,
+    QComboBox, QDate, QDateTime, QDateTimeEdit, QDialog, QDialogButtonBox, QFont,
+    QFontInfo, QFontMetrics, QFrame, QIcon, QKeySequence, QLabel, QLayout, QMenu,
+    QMimeData, QPainter, QPalette, QPixmap, QPoint, QPushButton, QRect, QScrollArea,
+    QSize, QSizePolicy, QStyle, QStyledItemDelegate, QStyleOptionToolButton,
+    QStylePainter, Qt, QTabWidget, QTextBrowser, QTextCursor, QToolButton, QUndoCommand,
+    QUndoStack, QUrl, QWidget, pyqtSignal,
 )
 
 from calibre.ebooks.metadata import rating_to_stars
@@ -19,6 +19,7 @@ from calibre.gui2.complete2 import EditWithComplete, LineEdit
 from calibre.gui2.widgets import history
 from calibre.utils.config_base import tweaks
 from calibre.utils.date import UNDEFINED_DATE
+from calibre.utils.localization import _
 from polyglot.functools import lru_cache
 
 
diff --git a/src/calibre/gui2/win_file_dialogs.py b/src/calibre/gui2/win_file_dialogs.py
index 20c0da112d..52e0587781 100644
--- a/src/calibre/gui2/win_file_dialogs.py
+++ b/src/calibre/gui2/win_file_dialogs.py
@@ -6,11 +6,11 @@ import os
 import struct
 import subprocess
 import sys
+from contextlib import suppress
 from threading import Thread
 from uuid import uuid4
-from contextlib import suppress
-
 
+from calibre.utils.localization import _
 from polyglot.builtins import string_or_bytes
 
 base = sys.extensions_location if hasattr(sys, 'new_app_layout') else os.path.dirname(sys.executable)
diff --git a/src/calibre/gui2/wizard/__init__.py b/src/calibre/gui2/wizard/__init__.py
index d4a691489e..1e42eabb0e 100644
--- a/src/calibre/gui2/wizard/__init__.py
+++ b/src/calibre/gui2/wizard/__init__.py
@@ -10,8 +10,8 @@ import re
 import traceback
 from contextlib import closing, suppress
 from qt.core import (
-    QAbstractListModel, QDir, QIcon, QItemSelection, QItemSelectionModel, Qt,
-    QWizard, QWizardPage, pyqtSignal
+    QAbstractListModel, QDir, QIcon, QItemSelection, QItemSelectionModel, Qt, QWizard,
+    QWizardPage, pyqtSignal,
 )
 
 from calibre import __appname__
@@ -24,7 +24,7 @@ from calibre.gui2.wizard.library_ui import Ui_WizardPage as LibraryUI
 from calibre.gui2.wizard.send_email import smtp_prefs
 from calibre.gui2.wizard.stanza_ui import Ui_WizardPage as StanzaUI
 from calibre.utils.config import dynamic, prefs
-from calibre.utils.localization import localize_user_manual_link
+from calibre.utils.localization import _, localize_user_manual_link
 from polyglot.builtins import iteritems
 
 # Devices {{{
@@ -717,7 +717,7 @@ class LibraryPage(QWizardPage, LibraryUI):
         self.language.blockSignals(True)
         self.language.clear()
         from calibre.utils.localization import (
-            available_translations, get_lang, get_language, get_lc_messages_path
+            available_translations, get_lang, get_language, get_lc_messages_path,
         )
         lang = get_lang()
         lang = get_lc_messages_path(lang) if lang else lang
diff --git a/src/calibre/gui2/wizard/send_email.py b/src/calibre/gui2/wizard/send_email.py
index 4701862742..8249790939 100644
--- a/src/calibre/gui2/wizard/send_email.py
+++ b/src/calibre/gui2/wizard/send_email.py
@@ -7,17 +7,17 @@ __docformat__ = 'restructuredtext en'
 
 import sys
 from functools import partial
+from qt.core import (
+    QCheckBox, QDialog, QDialogButtonBox, QGridLayout, QHBoxLayout, QIcon, QLabel,
+    QLineEdit, QPlainTextEdit, QPushButton, Qt, QVBoxLayout, QWidget, pyqtSignal,
+)
 from threading import Thread
 
-from qt.core import (
-    QWidget, pyqtSignal, QDialog, Qt, QLabel, QLineEdit, QDialogButtonBox,
-    QGridLayout, QCheckBox, QIcon, QVBoxLayout, QPushButton, QPlainTextEdit,
-    QHBoxLayout)
-
 from calibre import prints
-from calibre.gui2.wizard.send_email_ui import Ui_Form
-from calibre.utils.smtp import config as smtp_prefs
 from calibre.gui2 import error_dialog, question_dialog
+from calibre.gui2.wizard.send_email_ui import Ui_Form
+from calibre.utils.localization import _
+from calibre.utils.smtp import config as smtp_prefs
 from polyglot.binary import as_hex_unicode, from_hex_unicode
 from polyglot.io import PolyglotStringIO
 
@@ -211,7 +211,7 @@ class SendEmail(QWidget, Ui_Form):
 
     def test_email_settings(self, to):
         opts = smtp_prefs().parse()
-        from calibre.utils.smtp import sendmail, create_mail
+        from calibre.utils.smtp import create_mail, sendmail
         buf = PolyglotStringIO()
         debug_out = partial(prints, file=buf)
         oout, oerr = sys.stdout, sys.stderr
diff --git a/src/calibre/gui_launch.py b/src/calibre/gui_launch.py
index 4e48da22d2..e0bf492d2b 100644
--- a/src/calibre/gui_launch.py
+++ b/src/calibre/gui_launch.py
@@ -85,6 +85,7 @@ def is_possible_media_pack_error(e):
 def show_media_pack_error():
     import traceback
     from calibre.gui2 import error_dialog, Application
+    from calibre.utils.localization import _
     app = Application([])
     error_dialog(None, _('Required component missing'), '<p>' + _(
         'This computer is missing the Windows MediaPack, which is needed for calibre. Instructions'
diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index efc3994a1d..eed672e9f6 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -20,7 +20,7 @@ from calibre.ebooks.metadata.opf2 import metadata_to_opf
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.date import UNDEFINED_DATE, clean_date_for_sort, now, parse_date
 from calibre.utils.icu import lower as icu_lower
-from calibre.utils.localization import canonicalize_lang, get_udc, lang_map
+from calibre.utils.localization import _, canonicalize_lang, get_udc, lang_map
 from calibre.utils.search_query_parser import ParseException, SearchQueryParser
 from polyglot.builtins import cmp, iteritems, itervalues, string_or_bytes
 
diff --git a/src/calibre/library/catalogs/bibtex.py b/src/calibre/library/catalogs/bibtex.py
index 27feade593..ac2397c290 100644
--- a/src/calibre/library/catalogs/bibtex.py
+++ b/src/calibre/library/catalogs/bibtex.py
@@ -16,6 +16,7 @@ from calibre.customize import CatalogPlugin
 from calibre.customize.conversion import DummyReporter
 from calibre.ebooks.metadata import format_isbn
 from calibre.library.catalogs import FIELDS, TEMPLATE_ALLOWED_FIELDS
+from calibre.utils.localization import _
 from polyglot.builtins import string_or_bytes
 
 
diff --git a/src/calibre/library/catalogs/csv_xml.py b/src/calibre/library/catalogs/csv_xml.py
index 21ca37b42e..9e192620de 100644
--- a/src/calibre/library/catalogs/csv_xml.py
+++ b/src/calibre/library/catalogs/csv_xml.py
@@ -5,12 +5,15 @@ __license__ = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import re, codecs, os
+import codecs
+import os
+import re
 from collections import namedtuple
 
 from calibre.customize import CatalogPlugin
-from calibre.library.catalogs import FIELDS
 from calibre.customize.conversion import DummyReporter
+from calibre.library.catalogs import FIELDS
+from calibre.utils.localization import _
 
 
 class CSV_XML(CatalogPlugin):
@@ -50,12 +53,13 @@ class CSV_XML(CatalogPlugin):
                 "Applies to: CSV, XML output formats"))]
 
     def run(self, path_to_output, opts, db, notification=DummyReporter()):
+        from lxml import etree
+
+        from calibre.ebooks.metadata import authors_to_string
         from calibre.library import current_library_name
         from calibre.utils.date import isoformat
         from calibre.utils.html2text import html2text
         from calibre.utils.logging import default_log as log
-        from lxml import etree
-        from calibre.ebooks.metadata import authors_to_string
 
         self.fmt = path_to_output.rpartition('.')[2]
         self.notification = notification
diff --git a/src/calibre/library/catalogs/epub_mobi.py b/src/calibre/library/catalogs/epub_mobi.py
index 0586bf0345..ae95691c71 100644
--- a/src/calibre/library/catalogs/epub_mobi.py
+++ b/src/calibre/library/catalogs/epub_mobi.py
@@ -5,16 +5,20 @@ __license__ = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import datetime, os, time
+import datetime
+import os
+import time
 from collections import namedtuple
 
 from calibre import strftime
 from calibre.customize import CatalogPlugin
-from calibre.customize.conversion import OptionRecommendation, DummyReporter
+from calibre.customize.conversion import DummyReporter, OptionRecommendation
 from calibre.library import current_library_name
 from calibre.library.catalogs import AuthorSortMismatchException, EmptyCatalogException
 from calibre.ptempfile import PersistentTemporaryFile
-from calibre.utils.localization import calibre_langcode_to_name, canonicalize_lang, get_lang
+from calibre.utils.localization import (
+    _, calibre_langcode_to_name, canonicalize_lang, get_lang,
+)
 
 Option = namedtuple('Option', 'option, default, dest, action, help')
 
@@ -190,8 +194,8 @@ class EPUB_MOBI(CatalogPlugin):
 
     def run(self, path_to_output, opts, db, notification=DummyReporter()):
         from calibre.library.catalogs.epub_mobi_builder import CatalogBuilder
-        from calibre.utils.logging import default_log as log
         from calibre.utils.config import JSONConfig
+        from calibre.utils.logging import default_log as log
 
         # If preset specified from the cli, insert stored options from JSON file
         if hasattr(opts, 'preset') and opts.preset:
diff --git a/src/calibre/library/catalogs/epub_mobi_builder.py b/src/calibre/library/catalogs/epub_mobi_builder.py
index cf6578c5b5..ca67089c38 100644
--- a/src/calibre/library/catalogs/epub_mobi_builder.py
+++ b/src/calibre/library/catalogs/epub_mobi_builder.py
@@ -38,7 +38,7 @@ from calibre.utils.formatter import TemplateFormatter
 from calibre.utils.icu import (
     capitalize, collation_order, sort_key, title_case as icu_title, upper as icu_upper,
 )
-from calibre.utils.localization import get_lang, lang_as_iso639_1, ngettext
+from calibre.utils.localization import _, get_lang, lang_as_iso639_1, ngettext
 from calibre.utils.resources import get_image_path as I, get_path as P
 from calibre.utils.xml_parse import safe_xml_fromstring
 from calibre.utils.zipfile import ZipFile
diff --git a/src/calibre/library/check_library.py b/src/calibre/library/check_library.py
index 02926c3f3d..dedbfef5db 100644
--- a/src/calibre/library/check_library.py
+++ b/src/calibre/library/check_library.py
@@ -5,11 +5,15 @@ __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import re, os, traceback, fnmatch
+import fnmatch
+import os
+import re
+import traceback
 
 from calibre import isbytestring
 from calibre.constants import filesystem_encoding
 from calibre.ebooks import BOOK_EXTENSIONS
+from calibre.utils.localization import _
 from polyglot.builtins import iteritems
 
 EBOOK_EXTENSIONS = frozenset(BOOK_EXTENSIONS)
diff --git a/src/calibre/library/coloring.py b/src/calibre/library/coloring.py
index 65c2e90888..69caf8548e 100644
--- a/src/calibre/library/coloring.py
+++ b/src/calibre/library/coloring.py
@@ -6,6 +6,7 @@ import json
 import re
 from textwrap import dedent
 
+from calibre.utils.localization import _
 from polyglot.binary import as_hex_unicode, from_hex_bytes
 
 color_row_key = '*row'
diff --git a/src/calibre/library/custom_columns.py b/src/calibre/library/custom_columns.py
index 5033b4c40c..7d6fe96593 100644
--- a/src/calibre/library/custom_columns.py
+++ b/src/calibre/library/custom_columns.py
@@ -5,14 +5,17 @@ __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import json, re, numbers
+import json
+import numbers
+import re
 from functools import partial
 
-from calibre import prints, force_unicode
+from calibre import force_unicode, prints
 from calibre.constants import preferred_encoding
 from calibre.library.field_metadata import FieldMetadata
-from calibre.utils.date import parse_date
 from calibre.utils.config import tweaks
+from calibre.utils.date import parse_date
+from calibre.utils.localization import _
 from polyglot.builtins import string_or_bytes
 
 
@@ -217,7 +220,7 @@ class CustomColumns:
             if data['display'].get('sort_alpha', False):
                 ans.sort(key=lambda x:x.lower())
         if data['datatype'] == 'datetime' and isinstance(ans, string_or_bytes):
-            from calibre.db.tables import c_parse, UNDEFINED_DATE
+            from calibre.db.tables import UNDEFINED_DATE, c_parse
             ans = c_parse(ans)
             if ans is UNDEFINED_DATE:
                 ans = None
@@ -249,7 +252,7 @@ class CustomColumns:
             if data['display'].get('sort_alpha', False):
                 ans.sort(key=lambda x: x.lower())
         if data['datatype'] == 'datetime' and isinstance(ans, string_or_bytes):
-            from calibre.db.tables import c_parse, UNDEFINED_DATE
+            from calibre.db.tables import UNDEFINED_DATE, c_parse
             ans = c_parse(ans)
             if ans is UNDEFINED_DATE:
                 ans = None
diff --git a/src/calibre/library/database.py b/src/calibre/library/database.py
index 16757b20ac..7f43fbd8e1 100644
--- a/src/calibre/library/database.py
+++ b/src/calibre/library/database.py
@@ -5,14 +5,16 @@ __copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
 Backend that implements storage of ebooks in an sqlite database.
 '''
 
+import datetime
+import re
 import sqlite3 as sqlite
-import datetime, re, sre_constants
+import sre_constants
 from zlib import compress, decompress
 
-from calibre.ebooks.metadata import MetaInformation
-from calibre.ebooks.metadata import string_to_authors
-from calibre.utils.serialize import pickle_loads, pickle_dumps
 from calibre import isbytestring
+from calibre.ebooks.metadata import MetaInformation, string_to_authors
+from calibre.utils.localization import _
+from calibre.utils.serialize import pickle_dumps, pickle_loads
 
 
 class Concatenate:
@@ -980,7 +982,7 @@ ALTER TABLE books ADD COLUMN isbn TEXT DEFAULT "" COLLATE NOCASE;
         data = self.conn.get('SELECT data FROM covers WHERE book=?', (id,), all=False)
         if not data:
             return None
-        return(decompress(data))
+        return decompress(data)
 
     def tags(self, index, index_is_id=False):
         '''tags as a comma separated list or None'''
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 3ea0ecb429..1f63a0a59e 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -60,7 +60,7 @@ from calibre.utils.filenames import (
 from calibre.utils.formatter_functions import load_user_template_functions
 from calibre.utils.icu import lower, lower as icu_lower, sort_key, strcmp
 from calibre.utils.img import save_cover_data_to
-from calibre.utils.localization import calibre_langcode_to_name, canonicalize_lang
+from calibre.utils.localization import _, calibre_langcode_to_name, canonicalize_lang
 from calibre.utils.recycle_bin import delete_file, delete_tree
 from calibre.utils.resources import get_path as P
 from calibre.utils.search_query_parser import saved_searches, set_saved_searches
diff --git a/src/calibre/library/field_metadata.py b/src/calibre/library/field_metadata.py
index 07f27a0935..20dfd10bd5 100644
--- a/src/calibre/library/field_metadata.py
+++ b/src/calibre/library/field_metadata.py
@@ -9,7 +9,7 @@ from collections import OrderedDict
 
 from calibre.utils.config_base import tweaks
 from calibre.utils.icu import lower as icu_lower
-from calibre.utils.localization import ngettext
+from calibre.utils.localization import _, ngettext
 from polyglot.builtins import iteritems, itervalues
 
 category_icon_map = {
diff --git a/src/calibre/library/restore.py b/src/calibre/library/restore.py
index a071524779..f1e953721a 100644
--- a/src/calibre/library/restore.py
+++ b/src/calibre/library/restore.py
@@ -5,17 +5,21 @@ __license__   = 'GPL v3'
 __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import re, os, traceback, shutil
-from threading import Thread
+import os
+import re
+import shutil
+import traceback
 from operator import itemgetter
+from threading import Thread
 
-from calibre.ptempfile import TemporaryDirectory
+from calibre import isbytestring
+from calibre.constants import filesystem_encoding
 from calibre.ebooks.metadata.opf2 import OPF
 from calibre.library.database2 import LibraryDatabase2
 from calibre.library.prefs import DBPrefs
-from calibre.constants import filesystem_encoding
+from calibre.ptempfile import TemporaryDirectory
 from calibre.utils.date import utcfromtimestamp
-from calibre import isbytestring
+from calibre.utils.localization import _
 from polyglot.builtins import iteritems
 
 NON_EBOOK_EXTENSIONS = frozenset([
diff --git a/src/calibre/library/save_to_disk.py b/src/calibre/library/save_to_disk.py
index e6d19dca71..eac71e3b75 100644
--- a/src/calibre/library/save_to_disk.py
+++ b/src/calibre/library/save_to_disk.py
@@ -5,19 +5,21 @@ __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import os, traceback, re, errno
+import errno
+import os
+import re
+import traceback
 
-from calibre.constants import DEBUG
+from calibre import prints, sanitize_file_name, strftime
+from calibre.constants import DEBUG, preferred_encoding
 from calibre.db.errors import NoSuchFormat
-from calibre.utils.config import Config, StringConfig, tweaks
-from calibre.utils.formatter import TemplateFormatter
-from calibre.utils.filenames import shorten_components_to, ascii_filename
-from calibre.constants import preferred_encoding
-from calibre.ebooks.metadata import fmt_sidx
-from calibre.ebooks.metadata import title_sort
-from calibre.utils.date import as_local_time
-from calibre import strftime, prints, sanitize_file_name
 from calibre.db.lazy import FormatsList
+from calibre.ebooks.metadata import fmt_sidx, title_sort
+from calibre.utils.config import Config, StringConfig, tweaks
+from calibre.utils.date import as_local_time
+from calibre.utils.filenames import ascii_filename, shorten_components_to
+from calibre.utils.formatter import TemplateFormatter
+from calibre.utils.localization import _
 
 plugboard_any_device_value = 'any device'
 plugboard_any_format_value = 'any format'
diff --git a/src/calibre/linux.py b/src/calibre/linux.py
index f81de08db5..c201c136ff 100644
--- a/src/calibre/linux.py
+++ b/src/calibre/linux.py
@@ -15,6 +15,7 @@ from calibre import CurrentDir, __appname__, guess_type, prints
 from calibre.constants import isbsd, islinux
 from calibre.customize.ui import all_input_formats
 from calibre.ptempfile import TemporaryDirectory
+from calibre.utils.localization import _
 from calibre.utils.resources import get_image_path as I, get_path as P
 from polyglot.builtins import iteritems
 
diff --git a/src/calibre/spell/dictionary.py b/src/calibre/spell/dictionary.py
index 89042bcf63..4194a0ef50 100644
--- a/src/calibre/spell/dictionary.py
+++ b/src/calibre/spell/dictionary.py
@@ -16,7 +16,7 @@ from calibre.constants import config_dir, filesystem_encoding, iswindows
 from calibre.spell import parse_lang_code
 from calibre.utils.config import JSONConfig
 from calibre.utils.icu import capitalize
-from calibre.utils.localization import get_lang, get_system_locale
+from calibre.utils.localization import _, get_lang, get_system_locale
 from calibre.utils.resources import get_path as P
 from polyglot.builtins import iteritems, itervalues
 
diff --git a/src/calibre/srv/ajax.py b/src/calibre/srv/ajax.py
index 49055d2ca5..6fa95acab4 100644
--- a/src/calibre/srv/ajax.py
+++ b/src/calibre/srv/ajax.py
@@ -5,21 +5,24 @@ __license__ = 'GPL v3'
 __copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'
 
 from functools import partial
-from polyglot.builtins import iteritems, itervalues, string_or_bytes
 from itertools import cycle
 
 from calibre import force_unicode
-from calibre.library.field_metadata import category_icon_map
 from calibre.db.view import sanitize_sort_field_name
 from calibre.ebooks.metadata import title_sort
 from calibre.ebooks.metadata.book.json_codec import JsonCodec
-from calibre.srv.errors import HTTPNotFound, BookNotFound
-from calibre.srv.routes import endpoint, json
+from calibre.library.field_metadata import category_icon_map
 from calibre.srv.content import get as get_content, icon as get_icon
-from calibre.srv.utils import http_date, custom_fields_to_display, encode_name, decode_name, get_db
+from calibre.srv.errors import BookNotFound, HTTPNotFound
+from calibre.srv.routes import endpoint, json
+from calibre.srv.utils import (
+    custom_fields_to_display, decode_name, encode_name, get_db, http_date,
+)
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.date import isoformat, timestampfromdt
 from calibre.utils.icu import numeric_sort_key as sort_key
+from calibre.utils.localization import _
+from polyglot.builtins import iteritems, itervalues, string_or_bytes
 
 
 def ensure_val(x, *allowed):
@@ -126,9 +129,10 @@ def book_to_json(ctx, rd, db, book_id,
         data['_series_sort_'] = series
         if device_for_template:
             import posixpath
+
+            from calibre.customize.ui import device_plugins
             from calibre.devices.utils import create_upload_path
             from calibre.utils.filenames import ascii_filename as sanitize
-            from calibre.customize.ui import device_plugins
 
             for device_class in device_plugins():
                 if device_class.__class__.__name__ == device_for_template:
diff --git a/src/calibre/srv/books.py b/src/calibre/srv/books.py
index 3af369b0d8..f8e939aa08 100644
--- a/src/calibre/srv/books.py
+++ b/src/calibre/srv/books.py
@@ -21,6 +21,7 @@ from calibre.srv.render_book import RENDER_VERSION
 from calibre.srv.routes import endpoint, json
 from calibre.srv.utils import get_db, get_library_data
 from calibre.utils.filenames import rmtree
+from calibre.utils.localization import _
 from calibre.utils.resources import get_path as P
 from calibre.utils.serialize import json_dumps
 from polyglot.builtins import as_unicode, itervalues
diff --git a/src/calibre/srv/code.py b/src/calibre/srv/code.py
index 4fa3a4d2ab..41c71dbbba 100644
--- a/src/calibre/srv/code.py
+++ b/src/calibre/srv/code.py
@@ -27,7 +27,7 @@ from calibre.srv.utils import get_library_data, get_use_roman
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.icu import numeric_sort_key, sort_key
 from calibre.utils.localization import (
-    get_lang, lang_code_for_user_manual, lang_map_for_ui, localize_website_link,
+    _, get_lang, lang_code_for_user_manual, lang_map_for_ui, localize_website_link,
 )
 from calibre.utils.resources import get_path as P
 from calibre.utils.search_query_parser import ParseException
diff --git a/src/calibre/srv/content.py b/src/calibre/srv/content.py
index 91274eeb33..af28510b1f 100644
--- a/src/calibre/srv/content.py
+++ b/src/calibre/srv/content.py
@@ -28,6 +28,7 @@ from calibre.utils.config_base import tweaks
 from calibre.utils.date import timestampfromdt
 from calibre.utils.filenames import ascii_filename, atomic_rename
 from calibre.utils.img import image_from_data, scale_image
+from calibre.utils.localization import _
 from calibre.utils.resources import get_image_path as I, get_path as P
 from calibre.utils.shared_file import share_open
 from polyglot.binary import as_hex_unicode
diff --git a/src/calibre/srv/convert.py b/src/calibre/srv/convert.py
index cd2df6568e..b6407b3079 100644
--- a/src/calibre/srv/convert.py
+++ b/src/calibre/srv/convert.py
@@ -13,6 +13,7 @@ from calibre.srv.changes import formats_added
 from calibre.srv.errors import BookNotFound, HTTPNotFound
 from calibre.srv.routes import endpoint, json
 from calibre.srv.utils import get_library_data
+from calibre.utils.localization import _
 from calibre.utils.monotonic import monotonic
 from calibre.utils.shared_file import share_open
 from polyglot.builtins import iteritems
@@ -120,9 +121,9 @@ def convert_book(path_to_ebook, opf_path, cover_path, output_fmt, recs):
 
 
 def queue_job(ctx, rd, library_id, db, fmt, book_id, conversion_data):
-    from calibre.ebooks.metadata.opf2 import metadata_to_opf
-    from calibre.ebooks.conversion.config import GuiRecommendations, save_specifics
     from calibre.customize.conversion import OptionRecommendation
+    from calibre.ebooks.conversion.config import GuiRecommendations, save_specifics
+    from calibre.ebooks.metadata.opf2 import metadata_to_opf
     tdir = tempfile.mkdtemp(dir=rd.tdir)
     with tempfile.NamedTemporaryFile(prefix='', suffix=('.' + fmt.lower()), dir=tdir, delete=False) as src_file:
         db.copy_format_to(book_id, fmt, src_file)
@@ -202,10 +203,12 @@ def conversion_status(ctx, rd, job_id):
 
 
 def get_conversion_options(input_fmt, output_fmt, book_id, db):
-    from calibre.ebooks.conversion.plumber import create_dummy_plumber
-    from calibre.ebooks.conversion.config import (
-        load_specifics, load_defaults, OPTIONS, options_for_input_fmt, options_for_output_fmt)
     from calibre.customize.conversion import OptionRecommendation
+    from calibre.ebooks.conversion.config import (
+        OPTIONS, load_defaults, load_specifics, options_for_input_fmt,
+        options_for_output_fmt,
+    )
+    from calibre.ebooks.conversion.plumber import create_dummy_plumber
     plumber = create_dummy_plumber(input_fmt, output_fmt)
     specifics = load_specifics(db, book_id)
     ans = {'options': {}, 'disabled': set(), 'defaults': {}, 'help': {}}
@@ -265,7 +268,8 @@ def profiles():
 @endpoint('/conversion/book-data/{book_id}', postprocess=json, types={'book_id': int})
 def conversion_data(ctx, rd, book_id):
     from calibre.ebooks.conversion.config import (
-        NoSupportedInputFormats, get_input_format_for_book, get_sorted_output_formats)
+        NoSupportedInputFormats, get_input_format_for_book, get_sorted_output_formats,
+    )
     db = get_library_data(ctx, rd)[0]
     if not ctx.has_id(rd, db, book_id):
         raise BookNotFound(book_id, db)
diff --git a/src/calibre/srv/legacy.py b/src/calibre/srv/legacy.py
index 055228ebee..fa54504587 100644
--- a/src/calibre/srv/legacy.py
+++ b/src/calibre/srv/legacy.py
@@ -3,7 +3,6 @@
 
 
 from functools import partial
-
 from lxml.html import tostring
 from lxml.html.builder import E as E_
 
@@ -17,7 +16,8 @@ from calibre.srv.routes import endpoint
 from calibre.srv.utils import get_library_data, http_date
 from calibre.utils.cleantext import clean_xml_chars
 from calibre.utils.date import dt_as_local, is_date_undefined, timestampfromdt
-from polyglot.builtins import iteritems, string_or_bytes, as_bytes
+from calibre.utils.localization import _
+from polyglot.builtins import as_bytes, iteritems, string_or_bytes
 from polyglot.urllib import urlencode
 
 # /mobile {{{
diff --git a/src/calibre/srv/loop.py b/src/calibre/srv/loop.py
index 1a280c912c..c284b8b7a4 100644
--- a/src/calibre/srv/loop.py
+++ b/src/calibre/srv/loop.py
@@ -11,7 +11,7 @@ import socket
 import ssl
 import traceback
 from contextlib import suppress
-from functools import partial, lru_cache
+from functools import lru_cache, partial
 from io import BytesIO
 
 from calibre import as_unicode
@@ -23,8 +23,9 @@ from calibre.srv.opts import Options
 from calibre.srv.pool import PluginPool, ThreadPool
 from calibre.srv.utils import (
     DESIRED_SEND_BUFFER_SIZE, HandleInterrupt, create_sock_pair, socket_errors_eintr,
-    socket_errors_nonblocking, socket_errors_socket_closed, start_cork, stop_cork
+    socket_errors_nonblocking, socket_errors_socket_closed, start_cork, stop_cork,
 )
+from calibre.utils.localization import _
 from calibre.utils.logging import ThreadSafeLog
 from calibre.utils.mdns import get_external_ip
 from calibre.utils.monotonic import monotonic
diff --git a/src/calibre/srv/manage_users_cli.py b/src/calibre/srv/manage_users_cli.py
index 7544c9901d..87c7803201 100644
--- a/src/calibre/srv/manage_users_cli.py
+++ b/src/calibre/srv/manage_users_cli.py
@@ -7,7 +7,7 @@ from functools import partial
 from calibre import prints
 from calibre.constants import iswindows, preferred_encoding
 from calibre.utils.config import OptionParser
-from calibre.utils.localization import ngettext
+from calibre.utils.localization import _, ngettext
 from polyglot.builtins import iteritems
 
 
diff --git a/src/calibre/srv/metadata.py b/src/calibre/srv/metadata.py
index 8f3dabb16a..89e11ce94d 100644
--- a/src/calibre/srv/metadata.py
+++ b/src/calibre/srv/metadata.py
@@ -19,7 +19,7 @@ from calibre.utils.date import UNDEFINED_DATE, isoformat, local_tz
 from calibre.utils.file_type_icons import EXT_MAP
 from calibre.utils.formatter import EvalFormatter
 from calibre.utils.icu import collation_order_for_partitioning, upper as icu_upper
-from calibre.utils.localization import calibre_langcode_to_name
+from calibre.utils.localization import _, calibre_langcode_to_name
 from polyglot.builtins import iteritems, itervalues
 from polyglot.urllib import quote
 
diff --git a/src/calibre/srv/opds.py b/src/calibre/srv/opds.py
index 2ec3e0d242..0dd6ab8eb3 100644
--- a/src/calibre/srv/opds.py
+++ b/src/calibre/srv/opds.py
@@ -24,7 +24,7 @@ from calibre.srv.utils import Offsets, get_library_data, http_date
 from calibre.utils.config import prefs
 from calibre.utils.date import as_utc, is_date_undefined, timestampfromdt
 from calibre.utils.icu import sort_key
-from calibre.utils.localization import ngettext
+from calibre.utils.localization import _, ngettext
 from calibre.utils.search_query_parser import ParseException
 from calibre.utils.xml_parse import safe_xml_fromstring
 from polyglot.binary import as_hex_unicode, from_hex_unicode
diff --git a/src/calibre/srv/standalone.py b/src/calibre/srv/standalone.py
index 6bed06f780..5ad690e576 100644
--- a/src/calibre/srv/standalone.py
+++ b/src/calibre/srv/standalone.py
@@ -21,10 +21,10 @@ from calibre.srv.opts import opts_to_parser
 from calibre.srv.users import connect
 from calibre.srv.utils import HandleInterrupt, RotatingLog
 from calibre.utils.config import prefs
-from calibre.utils.localization import localize_user_manual_link
+from calibre.utils.localization import _, localize_user_manual_link
 from calibre.utils.lock import singleinstance
-from polyglot.builtins import error_message
 from calibre_extensions import speedup
+from polyglot.builtins import error_message
 
 
 def daemonize():  # {{{
diff --git a/src/calibre/srv/tests/ajax.py b/src/calibre/srv/tests/ajax.py
index 1b2da59a9d..62f6969522 100644
--- a/src/calibre/srv/tests/ajax.py
+++ b/src/calibre/srv/tests/ajax.py
@@ -12,6 +12,7 @@ from io import BytesIO
 
 from calibre.ebooks.metadata.meta import get_metadata
 from calibre.srv.tests.base import LibraryBaseTest
+from calibre.utils.localization import _
 from polyglot.binary import as_base64_bytes
 from polyglot.http_client import FORBIDDEN, NOT_FOUND, OK
 from polyglot.urllib import quote, urlencode
diff --git a/src/calibre/srv/users.py b/src/calibre/srv/users.py
index 2e211f4bb6..3b26d96921 100644
--- a/src/calibre/srv/users.py
+++ b/src/calibre/srv/users.py
@@ -12,6 +12,7 @@ from threading import RLock
 from calibre import as_unicode
 from calibre.constants import config_dir
 from calibre.utils.config import from_json, to_json
+from calibre.utils.localization import _
 from polyglot.builtins import iteritems
 
 
diff --git a/src/calibre/srv/users_api.py b/src/calibre/srv/users_api.py
index c7147a1983..2776104d84 100644
--- a/src/calibre/srv/users_api.py
+++ b/src/calibre/srv/users_api.py
@@ -8,6 +8,7 @@ from calibre import as_unicode
 from calibre.srv.errors import HTTPBadRequest, HTTPForbidden
 from calibre.srv.routes import endpoint
 from calibre.srv.users import validate_password
+from calibre.utils.localization import _
 
 
 @endpoint('/users/change-pw', methods={'POST'})
diff --git a/src/calibre/utils/config.py b/src/calibre/utils/config.py
index 91a5482280..dc2ac2e1ba 100644
--- a/src/calibre/utils/config.py
+++ b/src/calibre/utils/config.py
@@ -11,13 +11,14 @@ import os
 from copy import deepcopy
 
 from calibre.constants import (
-    CONFIG_DIR_MODE, __appname__, __author__, config_dir, get_version, iswindows
+    CONFIG_DIR_MODE, __appname__, __author__, config_dir, get_version, iswindows,
 )
 from calibre.utils.config_base import (
-    Config, ConfigInterface, ConfigProxy, Option, OptionSet, OptionValues,
-    StringConfig, commit_data, from_json, json_dumps, json_loads, make_config_dir,
-    plugin_dir, prefs, read_data, to_json, tweaks
+    Config, ConfigInterface, ConfigProxy, Option, OptionSet, OptionValues, StringConfig,
+    commit_data, from_json, json_dumps, json_loads, make_config_dir, plugin_dir, prefs,
+    read_data, to_json, tweaks,
 )
+from calibre.utils.localization import _
 from polyglot.builtins import native_string_type, string_or_bytes
 
 # optparse uses gettext.gettext instead of _ from builtins, so we
diff --git a/src/calibre/utils/config_base.py b/src/calibre/utils/config_base.py
index 2caeaea00a..0c8b1759a3 100644
--- a/src/calibre/utils/config_base.py
+++ b/src/calibre/utils/config_base.py
@@ -17,6 +17,7 @@ from calibre.constants import (
     CONFIG_DIR_MODE, config_dir, filesystem_encoding, get_umask, iswindows,
     preferred_encoding,
 )
+from calibre.utils.localization import _
 from calibre.utils.resources import get_path as P
 from polyglot.builtins import iteritems
 
diff --git a/src/calibre/utils/exim.py b/src/calibre/utils/exim.py
index dfc8865de4..b67fc08f20 100644
--- a/src/calibre/utils/exim.py
+++ b/src/calibre/utils/exim.py
@@ -2,20 +2,30 @@
 # License: GPLv3 Copyright: 2015, Kovid Goyal <kovid at kovidgoyal.net>
 
 
-import os, json, struct, hashlib, sys, errno, tempfile, time, shutil, uuid
+import errno
+import hashlib
+import json
+import os
+import shutil
+import struct
+import sys
+import tempfile
+import time
+import uuid
 from collections import Counter
 
 from calibre import prints
-from calibre.constants import config_dir, iswindows, filesystem_encoding
-from calibre.utils.config_base import prefs, StringConfig, create_global_prefs
+from calibre.constants import config_dir, filesystem_encoding, iswindows
 from calibre.utils.config import JSONConfig
+from calibre.utils.config_base import StringConfig, create_global_prefs, prefs
 from calibre.utils.filenames import samefile
-from polyglot.builtins import iteritems, error_message
+from calibre.utils.localization import _
 from polyglot.binary import as_hex_unicode
-
+from polyglot.builtins import error_message, iteritems
 
 # Export {{{
 
+
 def send_file(from_obj, to_obj, chunksize=1<<20):
     m = hashlib.sha1()
     while True:
@@ -169,8 +179,8 @@ def all_known_libraries():
 
 
 def export(destdir, library_paths=None, dbmap=None, progress1=None, progress2=None, abort=None):
-    from calibre.db.cache import Cache
     from calibre.db.backend import DB
+    from calibre.db.cache import Cache
     if library_paths is None:
         library_paths = all_known_libraries()
     dbmap = dbmap or {}
diff --git a/src/calibre/utils/filenames.py b/src/calibre/utils/filenames.py
index 0e6fd58635..90a6fb9cd8 100644
--- a/src/calibre/utils/filenames.py
+++ b/src/calibre/utils/filenames.py
@@ -7,14 +7,14 @@ import errno
 import os
 import shutil
 import time
+from contextlib import closing, suppress
 from math import ceil
-from contextlib import suppress, closing
 
 from calibre import force_unicode, isbytestring, prints, sanitize_file_name
 from calibre.constants import (
-    filesystem_encoding, iswindows, preferred_encoding, ismacos
+    filesystem_encoding, ismacos, iswindows, preferred_encoding,
 )
-from calibre.utils.localization import get_udc
+from calibre.utils.localization import _, get_udc
 from polyglot.builtins import iteritems, itervalues
 
 
@@ -331,6 +331,7 @@ class WindowsAtomicFolderMove:
 
     def __init__(self, path):
         from collections import defaultdict
+
         from calibre_extensions import winutil
         self.handle_map = {}
 
diff --git a/src/calibre/utils/html2text.py b/src/calibre/utils/html2text.py
index 82abab99e8..4ce9e0b1ec 100644
--- a/src/calibre/utils/html2text.py
+++ b/src/calibre/utils/html2text.py
@@ -2,6 +2,9 @@
 # License: GPLv3 Copyright: 2019, Kovid Goyal <kovid at kovidgoyal.net>
 
 
+from calibre.utils.localization import _
+
+
 def html2text(html, single_line_break=True):
     from html2text import HTML2Text
     import re
diff --git a/src/calibre/utils/ipc/job.py b/src/calibre/utils/ipc/job.py
index 9695235ea3..b1795e12ac 100644
--- a/src/calibre/utils/ipc/job.py
+++ b/src/calibre/utils/ipc/job.py
@@ -6,14 +6,15 @@ __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
 
-import time, io
+import io
+import time
 from itertools import count
 
 from calibre import prints
 from calibre.constants import DEBUG
-from polyglot.queue import Queue, Empty
+from calibre.utils.localization import _
 from polyglot.builtins import cmp
-
+from polyglot.queue import Empty, Queue
 
 job_counter = count()