Explicitly close some files (from issue #10093)
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index cf0f8e4..f01c65f 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -4160,7 +4160,8 @@
     def _test_module_encoding(self, path):
         path, _ = os.path.splitext(path)
         path += ".py"
-        codecs.open(path, 'r', 'utf8').read()
+        with codecs.open(path, 'r', 'utf8') as f:
+            f.read()
 
     def test_argparse_module_encoding(self):
         self._test_module_encoding(argparse.__file__)