bpo-31043: fixed test_datetime run twice. (GH-2891)

diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index bb22871f2b1528318cf67aedcf97b729e82caec6..d659f369d54e46fda5fd0d9309202fe8e68b7228 100644 (file)
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -50,8 +50,6 @@ for module, suffix in zip(test_modules, test_suffixes):
         cls.tearDownClass = tearDownClass
     all_test_classes.extend(test_classes)
 
-    all_test_classes.extend(test_classes)
-
 def test_main():
     run_unittest(*all_test_classes)