[Lint] Fix flake8 3.7 warnings

- Fix new flake8 warnings from latest version.
  Note: The `addSlash` variable was orphaned with no reference in
        Twisted or Deluge code so removed.

- Update pre-commit config
  - New pinned versions.
  - Fix prettier output.
  - Use new flake8 hook config and add naming plugin.

14 files changed, 41 insertions, 45 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 70306f6a8..1cebebd4e 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -10,12 +10,22 @@ repos:
         name: Fmt Black
         language_version: python3.6
   - repo: https://github.com/prettier/prettier
-    rev: 1.15.2
+    rev: 1.16.4
     hooks:
       - id: prettier
         name: Fmt Prettier
+        # Workaround to list modified files only.
+        args: [--list-different]
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: 3.7.7
+    hooks:
+      - id: flake8
+        name: Chk Flake8
+        additional_dependencies:
+          - flake8-isort==2.7
+          - pep8-naming==0.8.2
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v1.4.0
+    rev: v2.1.0
     hooks:
       - id: double-quote-string-fixer
         name: Fix Double-quotes
@@ -27,7 +37,3 @@ repos:
         args: [--fix=auto]
       - id: trailing-whitespace
         name: Fix Trailing whitespace
-      - id: flake8
-        name: Chk Flake8
-        additional_dependencies:
-          - flake8-isort==2.5
diff --git a/deluge/config.py b/deluge/config.py
index 29f28e479..c85299682 100644
--- a/deluge/config.py
+++ b/deluge/config.py
@@ -49,12 +49,12 @@ from codecs import getwriter
 from io import open
 from tempfile import NamedTemporaryFile
 
-import six.moves.cPickle as pickle
+import six.moves.cPickle as pickle  # noqa: N813
 
 from deluge.common import JSON_FORMAT, get_default_config_dir
 
 log = logging.getLogger(__name__)
-callLater = None  # Necessary for the config tests
+callLater = None  # noqa: N816 Necessary for the config tests
 
 
 def prop(func):
diff --git a/deluge/core/torrentmanager.py b/deluge/core/torrentmanager.py
index eb9e810f6..c92939c06 100644
--- a/deluge/core/torrentmanager.py
+++ b/deluge/core/torrentmanager.py
@@ -17,7 +17,7 @@ import os
 import time
 from tempfile import gettempdir
 
-import six.moves.cPickle as pickle
+import six.moves.cPickle as pickle  # noqa: N813
 from twisted.internet import defer, error, reactor, threads
 from twisted.internet.defer import Deferred, DeferredList
 from twisted.internet.task import LoopingCall
@@ -128,7 +128,7 @@ class TorrentManager(component.Component):
 
     """
 
-    callLater = reactor.callLater
+    callLater = reactor.callLater  # noqa: N815
 
     def __init__(self):
         component.Component.__init__(
diff --git a/deluge/plugins/Label/deluge/plugins/label/gtkui/submenu.py b/deluge/plugins/Label/deluge/plugins/label/gtkui/submenu.py
index b2df91fcd..c5f80e70c 100644
--- a/deluge/plugins/Label/deluge/plugins/label/gtkui/submenu.py
+++ b/deluge/plugins/Label/deluge/plugins/label/gtkui/submenu.py
@@ -31,7 +31,7 @@ del _
 
 class LabelMenu(MenuItem):
     def __init__(self):
-        MenuItem.__init__(self, _('Label'))
+        MenuItem.__init__(self, _('Label'))  # noqa: F821
 
         self.sub_menu = Menu()
         self.set_submenu(self.sub_menu)
@@ -52,7 +52,7 @@ class LabelMenu(MenuItem):
             self.sub_menu.remove(child)
         for label in [NO_LABEL] + list(labels):
             if label == NO_LABEL:
-                item = MenuItem(_(NO_LABEL))
+                item = MenuItem(_(NO_LABEL))  # noqa: F821
             else:
                 item = MenuItem(label.replace('_', '__'))
             item.connect('activate', self.on_select_label, label)
diff --git a/deluge/tests/test_core.py b/deluge/tests/test_core.py
index 4a990285d..5568a39bf 100644
--- a/deluge/tests/test_core.py
+++ b/deluge/tests/test_core.py
@@ -68,9 +68,6 @@ class RedirectResource(Resource):
 
 
 class TopLevelResource(Resource):
-
-    addSlash = True
-
     def __init__(self):
         Resource.__init__(self)
         self.putChild(b'cookie', CookieResource())
diff --git a/deluge/tests/test_httpdownloader.py b/deluge/tests/test_httpdownloader.py
index e20c541f5..ca9b8530c 100644
--- a/deluge/tests/test_httpdownloader.py
+++ b/deluge/tests/test_httpdownloader.py
@@ -91,9 +91,6 @@ class PartialDownloadResource(Resource):
 
 
 class TopLevelResource(Resource):
-
-    addSlash = True
-
     def __init__(self):
         Resource.__init__(self)
         self.putChild(b'cookie', CookieResource())
diff --git a/deluge/tests/twisted/plugins/delugereporter.py b/deluge/tests/twisted/plugins/delugereporter.py
index 340b61cb5..c2a7b52b5 100644
--- a/deluge/tests/twisted/plugins/delugereporter.py
+++ b/deluge/tests/twisted/plugins/delugereporter.py
@@ -19,8 +19,8 @@ from zope.interface import implements
 class _Reporter(object):
     implements(IPlugin, IReporter)
 
-    def __init__(  # NOQA: N803
-        self, name, module, description, longOpt, shortOpt, klass
+    def __init__(
+        self, name, module, description, longOpt, shortOpt, klass  # noqa: N803
     ):
         self.name = name
         self.module = module
diff --git a/deluge/ui/gtk3/common.py b/deluge/ui/gtk3/common.py
index a8b2ffffb..757c3de27 100644
--- a/deluge/ui/gtk3/common.py
+++ b/deluge/ui/gtk3/common.py
@@ -15,7 +15,7 @@ import os
 import shutil
 import sys
 
-import six.moves.cPickle as pickle
+import six.moves.cPickle as pickle  # noqa: N813
 from gi.repository.Gdk import SELECTION_CLIPBOARD
 from gi.repository.GdkPixbuf import Colorspace, Pixbuf
 from gi.repository.GLib import GError
diff --git a/deluge/ui/gtk3/files_tab.py b/deluge/ui/gtk3/files_tab.py
index 6c9b5c7fd..fad74bf03 100644
--- a/deluge/ui/gtk3/files_tab.py
+++ b/deluge/ui/gtk3/files_tab.py
@@ -12,7 +12,7 @@ from __future__ import division, unicode_literals
 import logging
 import os.path
 
-import six.moves.cPickle as pickle
+import six.moves.cPickle as pickle  # noqa: N813
 from gi.repository import Gio, Gtk
 from gi.repository.Gdk import DragAction, ModifierType, keyval_name
 from gi.repository.GObject import TYPE_UINT64
diff --git a/deluge/ui/gtk3/path_chooser.py b/deluge/ui/gtk3/path_chooser.py
index 4a3e7d64b..b7228415e 100644
--- a/deluge/ui/gtk3/path_chooser.py
+++ b/deluge/ui/gtk3/path_chooser.py
@@ -90,7 +90,7 @@ class PathChoosersHandler(component.Component):
             chooser.config_key_funcs[key][1](value)
 
         # Save to core
-        if key is not 'path_chooser_max_popup_rows':
+        if key != 'path_chooser_max_popup_rows':
             client.core.set_config({key: value})
         else:
             # Since the max rows value can be changed fast with a spinbutton, we
diff --git a/deluge/ui/gtk3/path_combo_chooser.py b/deluge/ui/gtk3/path_combo_chooser.py
index 041efdbf0..892b5b472 100755
--- a/deluge/ui/gtk3/path_combo_chooser.py
+++ b/deluge/ui/gtk3/path_combo_chooser.py
@@ -1237,7 +1237,7 @@ class PathChooserComboBox(Gtk.Box, StoredValuesPopup, GObject.GObject):
         folder_name = ''
         if self.show_folder_name_on_button or not self.path_entry_visible:
             folder_name = path_without_trailing_path_sep(text)
-            if folder_name is not '/' and os.path.basename(folder_name):
+            if folder_name != '/' and os.path.basename(folder_name):
                 folder_name = os.path.basename(folder_name)
         self.folder_name_label.set_text(folder_name)
         # Only trigger event if text has changed
diff --git a/deluge/ui/web/js/deluge-all/ConnectionManager.js b/deluge/ui/web/js/deluge-all/ConnectionManager.js
index 3d9c53592..001e46bb1 100644
--- a/deluge/ui/web/js/deluge-all/ConnectionManager.js
+++ b/deluge/ui/web/js/deluge-all/ConnectionManager.js
@@ -267,22 +267,19 @@ Deluge.ConnectionManager = Ext.extend(Ext.Window, {
             }
 
             var id = selected.id;
-            deluge.client.web.connect(
-                id,
-                {
-                    success: function(methods) {
-                        deluge.client.reloadMethods();
-                        deluge.client.on(
-                            'connected',
-                            function(e) {
-                                deluge.events.fire('connect');
-                            },
-                            this,
-                            { single: true }
-                        );
-                    },
-                }
-            );
+            deluge.client.web.connect(id, {
+                success: function(methods) {
+                    deluge.client.reloadMethods();
+                    deluge.client.on(
+                        'connected',
+                        function(e) {
+                            deluge.events.fire('connect');
+                        },
+                        this,
+                        { single: true }
+                    );
+                },
+            });
             this.hide();
         }
     },
diff --git a/deluge/ui/web/server.py b/deluge/ui/web/server.py
index cfd50cd2d..43c8bbd52 100644
--- a/deluge/ui/web/server.py
+++ b/deluge/ui/web/server.py
@@ -438,7 +438,6 @@ class ScriptResource(resource.Resource, component.Component):
 
 
 class TopLevel(resource.Resource):
-    addSlash = True
 
     __stylesheets = [
         'css/ext-all-notheme.css',
diff --git a/packaging/win32/deluge-bbfreeze.py b/packaging/win32/deluge-bbfreeze.py
index a58161882..5cd3e35a7 100644
--- a/packaging/win32/deluge-bbfreeze.py
+++ b/packaging/win32/deluge-bbfreeze.py
@@ -154,7 +154,7 @@ for script in script_list:
     os.remove(script)
 
 # Exclude files which are already included in GTK or Windows. Also exclude unneeded pygame dlls.
-excludeDlls = (
+exclude_dlls = (
     'MSIMG32.dll',
     'MSVCR90.dll',
     'MSVCP90.dll',
@@ -170,7 +170,7 @@ excludeDlls = (
     'SDL_image.dll',
     'SDL_ttf.dll',
 )
-for exclude_dll in excludeDlls:
+for exclude_dll in exclude_dlls:
     try:
         os.remove(os.path.join(build_dir, exclude_dll))
     except OSError:
@@ -224,14 +224,14 @@ for script in script_list:
     script_exe = os.path.splitext(os.path.basename(script))[0] + '.exe'
     # Don't add to dev build versions.
     if not re.search('[a-zA-Z_-]', build_version):
-        versionInfo = VersionInfo(
+        version_info = VersionInfo(
             build_version,
             description='Deluge Bittorrent Client',
             company='Deluge Team',
             product='Deluge',
             _copyright='Deluge Team',
         )
-        stamp(os.path.join(build_dir, script_exe), versionInfo)
+        stamp(os.path.join(build_dir, script_exe), version_info)
 
 # Copy version info to file for nsis script.
 with open('VERSION.tmp', 'w') as ver_file: