diff --git a/recipes/wenxuecity-znjy.recipe b/recipes/wenxuecity-znjy.recipe
index 56d834ff50..a3793eddf6 100644
--- a/recipes/wenxuecity-znjy.recipe
+++ b/recipes/wenxuecity-znjy.recipe
@@ -63,4 +63,3 @@ class TheCND(BasicNewsRecipe):
     def populate_article_metadata(self, article, soup, first):
         header = soup.find('h3')
         self.log('header: ' + self.tag_to_string(header))
-        pass
diff --git a/src/calibre/ebooks/metadata/meta.py b/src/calibre/ebooks/metadata/meta.py
index ac0fd27d01..03f2a2d6f9 100644
--- a/src/calibre/ebooks/metadata/meta.py
+++ b/src/calibre/ebooks/metadata/meta.py
@@ -227,7 +227,6 @@ def opf_metadata(opfpath):
     except Exception:
         import traceback
         traceback.print_exc()
-        pass
 
 
 def forked_read_metadata(original_path, tdir):
diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index 2900083f71..4170e484a9 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -1830,7 +1830,6 @@ class OEBBook:
                     self.spine.page_progression_direction = 'rtl'
             except Exception:
                 raise
-                pass
 
     def clean_temp_files(self):
         for path in self._temp_files:
diff --git a/src/calibre/ebooks/rtf2xml/preamble_div.py b/src/calibre/ebooks/rtf2xml/preamble_div.py
index bde0b04f91..c6989df5e5 100644
--- a/src/calibre/ebooks/rtf2xml/preamble_div.py
+++ b/src/calibre/ebooks/rtf2xml/preamble_div.py
@@ -342,7 +342,6 @@ cw<ci<font-style<nu<0
             pass
         else:
             self.__list_table_final += line
-            pass
 
     def __found_override_table_func(self, line):
         self.__override_table_obj = override_table.OverrideTable(
diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index 39f4bbeadb..bf77934571 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -202,8 +202,7 @@ def main(args=sys.argv):
     parser = option_parser()
     opts, args = parser.parse_args(args)
     oat = opts.open_at
-    if oat and not (
-            oat.startswith(('toc:', 'toc-href:', 'toc-href-contains:', 'epubcfi(/', 'ref:', 'search:', 'regex:')) or is_float(oat)):
+    if oat and not (oat.startswith(('toc:', 'toc-href:', 'toc-href-contains:', 'epubcfi(/', 'ref:', 'search:', 'regex:')) or is_float(oat)):
         raise SystemExit(f'Not a valid --open-at value: {opts.open_at}')
 
     if not opts.new_instance and get_session_pref('singleinstance', False):
diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index 134099049a..d027b07bb8 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -1017,8 +1017,7 @@ class PythonHighlighter(QSyntaxHighlighter):  # {{{
             self.setFormat(0, textLength,
                            self.Formats['error'])
             return
-        if prevState == ERROR and \
-           not (text.startswith(('>>>', '#'))):
+        if prevState == ERROR and not text.startswith(('>>>', '#')):
             self.setCurrentBlockState(ERROR)
             self.setFormat(0, textLength,
                            self.Formats['error'])
diff --git a/src/calibre/library/catalogs/epub_mobi_builder.py b/src/calibre/library/catalogs/epub_mobi_builder.py
index b6faad35e3..aa70dd2f0f 100644
--- a/src/calibre/library/catalogs/epub_mobi_builder.py
+++ b/src/calibre/library/catalogs/epub_mobi_builder.py
@@ -644,7 +644,6 @@ class CatalogBuilder:
                     except:
                         if self.opts.verbose:
                             self.opts.log.error('pattern failed to compile: %s' % rule['pattern'])
-                        pass
                 elif field_contents is None and rule['pattern'] == 'None':
                     if self.DEBUG:
                         _log_prefix_rule_match_info(rule, record, field_contents)
diff --git a/src/calibre/web/feeds/news.py b/src/calibre/web/feeds/news.py
index 4cab2dcf87..475b4a53ef 100644
--- a/src/calibre/web/feeds/news.py
+++ b/src/calibre/web/feeds/news.py
@@ -1108,7 +1108,6 @@ class BasicNewsRecipe(Recipe):
                 article = self.feed_objects[f].articles[a]
             except:
                 self.log.exception('Failed to get article object for postprocessing')
-                pass
             else:
                 self.populate_article_metadata(article, ans, first_fetch)
         return ans
diff --git a/src/calibre/web/feeds/recipes/collection.py b/src/calibre/web/feeds/recipes/collection.py
index 25ef7d4e37..42d6ef7b47 100644
--- a/src/calibre/web/feeds/recipes/collection.py
+++ b/src/calibre/web/feeds/recipes/collection.py
@@ -75,7 +75,15 @@ def serialize_recipe(urn, recipe_class):
     if rso:
         options = f' options={quoteattr(json.dumps(rso))}'
     return ('  <recipe id={id} title={title} author={author} language={language}'
-            ' needs_subscription={needs_subscription} description={description}{options}/>').format(id=quoteattr(str(urn)), title=attr('title', _('Unknown')), author=attr('__author__', default_author), language=attr('language', 'und', normalize_language), needs_subscription=quoteattr(ns), description=attr('description', ''), options=options)
+            ' needs_subscription={needs_subscription} description={description}{options}/>').format(
+                id=quoteattr(str(urn)),
+                title=attr('title', _('Unknown')),
+                author=attr('__author__', default_author),
+                language=attr('language', 'und', normalize_language),
+                needs_subscription=quoteattr(ns),
+                description=attr('description', ''),
+                options=options,
+            )
 
 
 def serialize_collection(mapping_of_recipe_classes):