diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index d3b5c29cbb7..8ea058fc6da 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -552,12 +552,11 @@ class HTTPRedirectHandler(BaseHandler):
         # For security reasons we don't allow redirection to anything other
         # than http, https or ftp.
 
-        if not urlparts.scheme in ('http', 'https', 'ftp'):
-            raise HTTPError(newurl, code,
-                            msg +
-                            " - Redirection to url '%s' is not allowed" %
-                            newurl,
-                            headers, fp)
+        if urlparts.scheme not in ('http', 'https', 'ftp'):
+            raise HTTPError(
+                newurl, code,
+                "%s - Redirection to url '%s' is not allowed" % (msg, newurl),
+                headers, fp)
 
         if not urlparts.path:
             urlparts = list(urlparts)
@@ -722,7 +721,7 @@ class HTTPPasswordMgr:
         # uri could be a single URI or a sequence
         if isinstance(uri, str):
             uri = [uri]
-        if not realm in self.passwd:
+        if realm not in self.passwd:
             self.passwd[realm] = {}
         for default_port in True, False:
             reduced_uri = tuple(
@@ -1823,7 +1822,7 @@ class URLopener:
                     del self.ftpcache[k]
                     v.close()
         try:
-            if not key in self.ftpcache:
+            if key not in self.ftpcache:
                 self.ftpcache[key] = \
                     ftpwrapper(user, passwd, host, port, dirs)
             if not file: type = 'D'
@@ -1938,7 +1937,7 @@ class FancyURLopener(URLopener):
         # We are using newer HTTPError with older redirect_internal method
         # This older method will get deprecated in 3.3
 
-        if not urlparts.scheme in ('http', 'https', 'ftp'):
+        if urlparts.scheme not in ('http', 'https', 'ftp'):
             raise HTTPError(newurl, errcode,
                             errmsg +
                             " Redirection to url '%s' is not allowed." % newurl,
@@ -1965,7 +1964,7 @@ class FancyURLopener(URLopener):
             retry=False):
         """Error 401 -- authentication required.
         This function supports Basic authentication only."""
-        if not 'www-authenticate' in headers:
+        if 'www-authenticate' not in headers:
             URLopener.http_error_default(self, url, fp,
                                          errcode, errmsg, headers)
         stuff = headers['www-authenticate']
@@ -1991,7 +1990,7 @@ class FancyURLopener(URLopener):
             retry=False):
         """Error 407 -- proxy authentication required.
         This function supports Basic authentication only."""
-        if not 'proxy-authenticate' in headers:
+        if 'proxy-authenticate' not in headers:
             URLopener.http_error_default(self, url, fp,
                                          errcode, errmsg, headers)
         stuff = headers['proxy-authenticate']