Issue #21481: Teach argparse equality tests to return NotImplemented when comparing to unknown types.
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 5c77ec8..8a4fdb9 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -4551,6 +4551,12 @@
self.assertTrue(ns2 != ns3)
self.assertTrue(ns2 != ns4)
+ def test_equality_returns_notimplemeted(self):
+ # See issue 21481
+ ns = argparse.Namespace(a=1, b=2)
+ self.assertIs(ns.__eq__(None), NotImplemented)
+ self.assertIs(ns.__ne__(None), NotImplemented)
+
# ===================
# File encoding tests