diff --git a/sphinx/builders/_epub_base.py b/sphinx/builders/_epub_base.py
index 453687978..d17361a21 100644
--- a/sphinx/builders/_epub_base.py
+++ b/sphinx/builders/_epub_base.py
@@ -703,7 +703,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
         epub_filename = path.join(self.outdir, outname)
         with ZipFile(epub_filename, 'w', ZIP_DEFLATED) as epub:
             epub.write(path.join(self.outdir, 'mimetype'), 'mimetype', ZIP_STORED)
-            for filename in ['META-INF/container.xml', 'content.opf', 'toc.ncx']:
+            for filename in ('META-INF/container.xml', 'content.opf', 'toc.ncx'):
                 epub.write(path.join(self.outdir, filename), filename, ZIP_DEFLATED)
             for filename in self.files:
                 epub.write(path.join(self.outdir, filename), filename, ZIP_DEFLATED)
diff --git a/sphinx/builders/changes.py b/sphinx/builders/changes.py
index 0086fa158..a80e53d9a 100644
--- a/sphinx/builders/changes.py
+++ b/sphinx/builders/changes.py
@@ -148,7 +148,7 @@ class ChangesBuilder(Builder):
 
     def hl(self, text: str, version: str) -> str:
         text = html.escape(text)
-        for directive in ['versionchanged', 'versionadded', 'deprecated']:
+        for directive in ('versionchanged', 'versionadded', 'deprecated'):
             text = text.replace('.. %s:: %s' % (directive, version),
                                 '<b>.. %s:: %s</b>' % (directive, version))
         return text
diff --git a/sphinx/domains/c.py b/sphinx/domains/c.py
index 6ed4f1559..74556c3be 100644
--- a/sphinx/domains/c.py
+++ b/sphinx/domains/c.py
@@ -217,7 +217,7 @@ class ASTNestedName(ASTBase):
             assert not self.rooted, str(self)
             assert len(self.names) == 1
             self.names[0].describe_signature(signode, 'noneIsName', env, '', symbol)
-        elif mode == 'markType' or mode == 'lastIsName' or mode == 'markName':
+        elif mode in ('markType', 'lastIsName', 'markName'):
             # Each element should be a pending xref targeting the complete
             # prefix.
             prefix = ''
diff --git a/sphinx/domains/cpp.py b/sphinx/domains/cpp.py
index c8625e81d..30772c105 100644
--- a/sphinx/domains/cpp.py
+++ b/sphinx/domains/cpp.py
@@ -776,7 +776,7 @@ class ASTNestedName(ASTBase):
             assert len(self.names) == 1
             assert not self.templates[0]
             self.names[0].describe_signature(signode, 'param', env, '', symbol)
-        elif mode == 'markType' or mode == 'lastIsName' or mode == 'markName':
+        elif mode in ('markType', 'lastIsName', 'markName'):
             # Each element should be a pending xref targeting the complete
             # prefix. however, only the identifier part should be a link, such
             # that template args can be a link as well.
@@ -5385,7 +5385,7 @@ class DefinitionParser(BaseParser):
         postFixes: List[ASTPostfixOp] = []
         while True:
             self.skip_ws()
-            if prefixType in ['expr', 'cast', 'typeid']:
+            if prefixType in ('expr', 'cast', 'typeid'):
                 if self.skip_string_and_ws('['):
                     expr = self._parse_expression()
                     self.skip_ws()
@@ -7781,7 +7781,7 @@ class CPPDomain(Domain):
                             typ: str, target: str, node: pending_xref,
                             contnode: Element) -> Tuple[Optional[Element], Optional[str]]:
         # add parens again for those that could be functions
-        if typ == 'any' or typ == 'func':
+        if typ in ('any', 'func'):
             target += '()'
         parser = DefinitionParser(target, location=node, config=env.config)
         try:
@@ -7902,7 +7902,7 @@ class CPPDomain(Domain):
                     if (env.config.add_function_parentheses and typ == 'func' and
                             title.endswith('operator()')):
                         addParen += 1
-                    if ((typ == 'any' or typ == 'func') and
+                    if (typ in ('any', 'func') and
                             title.endswith('operator') and
                             displayName.endswith('operator()')):
                         addParen += 1
diff --git a/sphinx/ext/napoleon/__init__.py b/sphinx/ext/napoleon/__init__.py
index 557ed7735..fab918d41 100644
--- a/sphinx/ext/napoleon/__init__.py
+++ b/sphinx/ext/napoleon/__init__.py
@@ -444,10 +444,10 @@ def _skip_member(app: Sphinx, what: str, name: str, obj: Any,
 
     """
     has_doc = getattr(obj, '__doc__', False)
-    is_member = (what == 'class' or what == 'exception' or what == 'module')
+    is_member = what in ('class', 'exception', 'module')
     if name != '__weakref__' and has_doc and is_member:
         cls_is_owner = False
-        if what == 'class' or what == 'exception':
+        if what in ('class', 'exception'):
             qualname = getattr(obj, '__qualname__', '')
             cls_path, _, _ = qualname.rpartition('.')
             if cls_path:
diff --git a/sphinx/util/logging.py b/sphinx/util/logging.py
index bcf8bf63d..7294885b5 100644
--- a/sphinx/util/logging.py
+++ b/sphinx/util/logging.py
@@ -375,12 +375,8 @@ def is_suppressed_warning(type: str, subtype: str, suppress_warnings: List[str])
         else:
             target, subtarget = warning_type, None
 
-        if target == type:
-            if ((subtype is None and subtarget is None) or
-                    subtarget is None or
-                    subtarget == subtype or
-                    subtarget == '*'):
-                return True
+        if target == type and subtarget in (None, subtype, "*"):
+            return True
 
     return False
 
diff --git a/sphinx/util/stemmer/porter.py b/sphinx/util/stemmer/porter.py
index 55e2d329d..52ca31e0c 100644
--- a/sphinx/util/stemmer/porter.py
+++ b/sphinx/util/stemmer/porter.py
@@ -123,7 +123,7 @@ class PorterStemmer:
            or not self.cons(i - 2):
             return 0
         ch = self.b[i]
-        if ch == 'w' or ch == 'x' or ch == 'y':
+        if ch in ('w', 'x', 'y'):
             return 0
         return 1
 
@@ -193,7 +193,7 @@ class PorterStemmer:
             elif self.doublec(self.k):
                 self.k = self.k - 1
                 ch = self.b[self.k]
-                if ch == 'l' or ch == 's' or ch == 'z':
+                if ch in ('l', 's', 'z'):
                     self.k = self.k + 1
             elif (self.m() == 1 and self.cvc(self.k)):
                 self.setto("e")