It helps when doing checks if something is in a tuple of strings that if you

put everything in the tuple in caps to use str.upper() instead of str.lower().

Lib/test/test_strptime.py

@@ -280,7 +280,7 @@ class StrptimeTests(unittest.TestCase):
         if sys.platform == "mac":
             return #MacOS9 has severely broken timezone support.
         tz_name = time.tzname[0]
-        if tz_name.lower() in ("UTC", "GMT"):
+        if tz_name.upper() in ("UTC", "GMT"):
             return
         try:
             original_tzname = time.tzname