diff --git a/src/calibre/customize/zipplugin.py b/src/calibre/customize/zipplugin.py
index 749fd34acb..72bb7da4c4 100644
--- a/src/calibre/customize/zipplugin.py
+++ b/src/calibre/customize/zipplugin.py
@@ -144,7 +144,7 @@ class CalibrePluginLoader:
         'fullname_in_plugin',
         'names',
         'plugin_name',
-        'zip_file_path'
+        'zip_file_path',
     )
 
     def __init__(self, plugin_name, fullname_in_plugin, zip_file_path, names, filename, is_package, all_names):
diff --git a/src/calibre/ebooks/metadata/sources/base.py b/src/calibre/ebooks/metadata/sources/base.py
index ac8644a10a..84d6ca522a 100644
--- a/src/calibre/ebooks/metadata/sources/base.py
+++ b/src/calibre/ebooks/metadata/sources/base.py
@@ -164,7 +164,7 @@ def fixcase(x):
 
 
 class Option:
-    __slots__ = ['choices', 'default', 'desc', 'label', 'name', 'type']
+    __slots__ = ('choices', 'default', 'desc', 'label', 'name', 'type')
 
     def __init__(self, name, type_, default, label, desc, choices=None):
         '''
diff --git a/src/calibre/gui2/tweak_book/live_css.py b/src/calibre/gui2/tweak_book/live_css.py
index efae140bc5..faca55cec6 100644
--- a/src/calibre/gui2/tweak_book/live_css.py
+++ b/src/calibre/gui2/tweak_book/live_css.py
@@ -386,7 +386,7 @@ class Box(QWidget):
 
 class Property:
 
-    __slots__ = 'color', 'important', 'is_overriden', 'name', 'specificity', 'value'
+    __slots__ = ('color', 'important', 'is_overriden', 'name', 'specificity', 'value')
 
     def __init__(self, prop, specificity=()):
         self.name, self.value, self.important, self.color = prop
diff --git a/src/calibre/gui2/viewer/search.py b/src/calibre/gui2/viewer/search.py
index c85bd88f01..948501644b 100644
--- a/src/calibre/gui2/viewer/search.py
+++ b/src/calibre/gui2/viewer/search.py
@@ -194,7 +194,7 @@ class SearchResult:
         'search_query',
         'spine_idx',
         'text',
-        'toc_nodes'
+        'toc_nodes',
     )
 
     def __init__(self, search_query, before, text, after, q, name, spine_idx, index, offset, result_num):
diff --git a/src/calibre/utils/matcher.py b/src/calibre/utils/matcher.py
index 2131855981..35097adedd 100644
--- a/src/calibre/utils/matcher.py
+++ b/src/calibre/utils/matcher.py
@@ -231,7 +231,7 @@ class PyScorer:
         'level2',
         'level3',
         'max_score_per_char',
-        'memory'
+        'memory',
     )
 
     def __init__(
diff --git a/src/calibre/utils/threadpool.py b/src/calibre/utils/threadpool.py
index ce5770c26e..4dffda8ff8 100644
--- a/src/calibre/utils/threadpool.py
+++ b/src/calibre/utils/threadpool.py
@@ -36,7 +36,7 @@ __all__ = [
     'ThreadPool',
     'WorkRequest',
     'WorkerThread',
-    'makeRequests'
+    'makeRequests',
 ]
 
 __author__ = 'Christopher Arndt'
diff --git a/src/calibre/utils/zipfile.py b/src/calibre/utils/zipfile.py
index 13e0ddcff9..8e8dab6340 100644
--- a/src/calibre/utils/zipfile.py
+++ b/src/calibre/utils/zipfile.py
@@ -334,7 +334,7 @@ class ZipInfo :
         'orig_filename',
         'reserved',
         'volume',
-        )
+    )
 
     def __init__(self, filename='NoName', date_time=(1980,1,1,0,0,0)):
         self.orig_filename = filename   # Original file name in archive