diff --git a/src/calibre/ebooks/lrf/pylrs/pylrs.py b/src/calibre/ebooks/lrf/pylrs/pylrs.py
index 47bf8181ea..9c08c554c2 100644
--- a/src/calibre/ebooks/lrf/pylrs/pylrs.py
+++ b/src/calibre/ebooks/lrf/pylrs/pylrs.py
@@ -1042,7 +1042,6 @@ class BookStyle(LrsObject, LrsContainer):
     def Font(self, *args, **kwargs):
         f = Font(*args, **kwargs)
         self.append(f)
-        return
 
     def toElement(self, se):
         bookStyle = self.lrsObjectElement('BookStyle', objlabel='stylelabel',
diff --git a/src/calibre/ebooks/metadata/mobi.py b/src/calibre/ebooks/metadata/mobi.py
index 66d46a79b8..18c6e4f579 100644
--- a/src/calibre/ebooks/metadata/mobi.py
+++ b/src/calibre/ebooks/metadata/mobi.py
@@ -473,7 +473,6 @@ class MetadataUpdater:
 def set_metadata(stream, mi):
     mu = MetadataUpdater(stream)
     mu.update(mi)
-    return
 
 
 def get_metadata(stream):
diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index d9de0a3283..71ca480ae9 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -1930,7 +1930,6 @@ class OEBBook:
             href = urlnormalize(selector(elem)[0])
             order = playorder.get(href, i)
             elem.attrib['playOrder'] = str(order)
-        return
 
     def _to_ncx(self):
         try:
diff --git a/src/calibre/ebooks/snb/snbfile.py b/src/calibre/ebooks/snb/snbfile.py
index d92018fb3c..f5e8974d99 100644
--- a/src/calibre/ebooks/snb/snbfile.py
+++ b/src/calibre/ebooks/snb/snbfile.py
@@ -278,7 +278,6 @@ class SNBFile:
 
         # Close
         outputFile.close()
-        return
 
     def Dump(self):
         if self.fileName:
diff --git a/src/calibre/gui2/dialogs/template_dialog.py b/src/calibre/gui2/dialogs/template_dialog.py
index 1a7b05eaca..fe8e480e5d 100644
--- a/src/calibre/gui2/dialogs/template_dialog.py
+++ b/src/calibre/gui2/dialogs/template_dialog.py
@@ -1011,7 +1011,6 @@ def evaluate(book, context):
                 self.icon_files.adjustSize()
         except:
             traceback.print_exc()
-        return
 
     def update_filename_box(self):
         self.icon_files.clear()
diff --git a/src/calibre/gui2/library/delegates.py b/src/calibre/gui2/library/delegates.py
index 324fa95572..e9c85db96f 100644
--- a/src/calibre/gui2/library/delegates.py
+++ b/src/calibre/gui2/library/delegates.py
@@ -610,7 +610,6 @@ class CcLongTextDelegate(StyledItemDelegate):  # {{{
         d = PlainTextDialog(parent, text, column_name=m.custom_columns[col]['name'])
         if d.exec() == QDialog.DialogCode.Accepted:
             m.setData(index, d.text, Qt.ItemDataRole.EditRole)
-        return
 
     def setModelData(self, editor, model, index):
         model.setData(index, (editor.textbox.html), Qt.ItemDataRole.EditRole)
@@ -665,7 +664,6 @@ class CcMarkdownDelegate(StyledItemDelegate):  # {{{
                                base_url=base_url)
         if d.exec() == QDialog.DialogCode.Accepted:
             m.setData(index, (d.text), Qt.ItemDataRole.EditRole)
-        return
 
     def setModelData(self, editor, model, index):
         model.setData(index, (editor.textbox.html), Qt.ItemDataRole.EditRole)
@@ -816,7 +814,6 @@ class CcCommentsDelegate(StyledItemDelegate):  # {{{
         d = editor.exec()
         if d:
             m.setData(index, (editor.textbox.html), Qt.ItemDataRole.EditRole)
-        return
 
     def setModelData(self, editor, model, index):
         model.setData(index, (editor.textbox.html), Qt.ItemDataRole.EditRole)
diff --git a/src/calibre/gui2/metadata/basic_widgets.py b/src/calibre/gui2/metadata/basic_widgets.py
index 52d03a22dd..0231432cf3 100644
--- a/src/calibre/gui2/metadata/basic_widgets.py
+++ b/src/calibre/gui2/metadata/basic_widgets.py
@@ -1022,15 +1022,13 @@ class FormatsManager(QWidget):
                 db.add_format(id_, ext, spool, notify=False,
                         index_is_id=True)
         dbfmts = db.formats(id_, index_is_id=True)
-        db_extensions = {fl.lower() for fl in (dbfmts.split(',') if dbfmts
-            else [])}
+        db_extensions = {fl.lower() for fl in (dbfmts.split(',') if dbfmts else [])}
         extensions = new_extensions.union(old_extensions)
         for ext in db_extensions:
             if ext not in extensions and ext in self.original_val:
                 db.remove_format(id_, ext, notify=False, index_is_id=True)
 
         self.changed = False
-        return
 
     def add_format(self, *args):
         files = choose_files_and_remember_all_files(
diff --git a/src/calibre/gui2/preferences/coloring.py b/src/calibre/gui2/preferences/coloring.py
index e15b5b6926..fe85325ded 100644
--- a/src/calibre/gui2/preferences/coloring.py
+++ b/src/calibre/gui2/preferences/coloring.py
@@ -677,7 +677,6 @@ class RuleEditor(QDialog):  # {{{
         except:
             import traceback
             traceback.print_exc()
-        return
 
     def get_filenames_from_box(self):
         if self.doing_multiple:
diff --git a/src/calibre/gui2/ui.py b/src/calibre/gui2/ui.py
index c649463898..3d8765a61b 100644
--- a/src/calibre/gui2/ui.py
+++ b/src/calibre/gui2/ui.py
@@ -764,7 +764,6 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, EmailMixin,  # {{{
                 item_val = itemx[4:]
             else:
                 prints('Ignoring invalid item hexval', itemx, file=sys.stderr)
-                return
 
             def doit():
                 nonlocal item_id, item_val
diff --git a/src/calibre/scraper/webengine_backend.py b/src/calibre/scraper/webengine_backend.py
index 3e736d82bd..27b342f0b0 100644
--- a/src/calibre/scraper/webengine_backend.py
+++ b/src/calibre/scraper/webengine_backend.py
@@ -118,7 +118,6 @@ class Worker(QWebEnginePage):
                     self.runjs('window.get_messages()', self.dispatch_messages)
             else:
                 print(f'{source_id}:{line_num}:{message}')
-            return
 
     def dispatch_messages(self, messages: list) -> None:
         if not sip.isdeleted(self):