bpo-37330: open() no longer accept 'U' in file mode (GH-16959)
open(), io.open(), codecs.open() and fileinput.FileInput no longer
accept "U" ("universal newline") in the file mode. This flag was
deprecated since Python 3.3.diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
index b37525b..e1638c1 100644
--- a/Lib/test/test_codecs.py
+++ b/Lib/test/test_codecs.py
@@ -712,11 +712,23 @@
self.addCleanup(support.unlink, support.TESTFN)
with open(support.TESTFN, 'wb') as fp:
fp.write(s)
- with support.check_warnings(('', DeprecationWarning)):
- reader = codecs.open(support.TESTFN, 'U', encoding=self.encoding)
- with reader:
+ with codecs.open(support.TESTFN, 'r',
+ encoding=self.encoding) as reader:
self.assertEqual(reader.read(), s1)
+ def test_invalid_modes(self):
+ for mode in ('U', 'rU', 'r+U'):
+ with self.assertRaises(ValueError) as cm:
+ codecs.open(support.TESTFN, mode, encoding=self.encoding)
+ self.assertIn('invalid mode', str(cm.exception))
+
+ for mode in ('rt', 'wt', 'at', 'r+t'):
+ with self.assertRaises(ValueError) as cm:
+ codecs.open(support.TESTFN, mode, encoding=self.encoding)
+ self.assertIn("can't have text and binary mode at once",
+ str(cm.exception))
+
+
class UTF16LETest(ReadTest, unittest.TestCase):
encoding = "utf-16-le"
ill_formed_sequence = b"\x80\xdc"