bpo-39674: Revert "bpo-37330: open() no longer accept 'U' in file mode (GH-16959)" (GH-18767)
This reverts commit e471e72977c83664f13d041c78549140c86c92de.
The mode will be removed from Python 3.10.
diff --git a/Lib/test/test_fileinput.py b/Lib/test/test_fileinput.py
index 819557d..014f19e 100644
--- a/Lib/test/test_fileinput.py
+++ b/Lib/test/test_fileinput.py
@@ -226,11 +226,19 @@
self.assertEqual(fi.fileno(), -1)
def test_opening_mode(self):
- # invalid modes
- for mode in ('w', 'rU', 'U'):
- with self.subTest(mode=mode):
- with self.assertRaises(ValueError):
- FileInput(mode=mode)
+ try:
+ # invalid mode, should raise ValueError
+ fi = FileInput(mode="w")
+ self.fail("FileInput should reject invalid mode argument")
+ except ValueError:
+ pass
+ # try opening in universal newline mode
+ t1 = self.writeTmp(b"A\nB\r\nC\rD", mode="wb")
+ with check_warnings(('', DeprecationWarning)):
+ fi = FileInput(files=t1, mode="U")
+ with check_warnings(('', DeprecationWarning)):
+ lines = list(fi)
+ self.assertEqual(lines, ["A\n", "B\n", "C\n", "D"])
def test_stdin_binary_mode(self):
with mock.patch('sys.stdin') as m_stdin:
@@ -977,6 +985,10 @@
self.assertEqual(lines, expected_lines)
check('r', ['A\n', 'B\n', 'C\n', 'D\u20ac'])
+ with self.assertWarns(DeprecationWarning):
+ check('rU', ['A\n', 'B\n', 'C\n', 'D\u20ac'])
+ with self.assertWarns(DeprecationWarning):
+ check('U', ['A\n', 'B\n', 'C\n', 'D\u20ac'])
with self.assertRaises(ValueError):
check('rb', ['A\n', 'B\r\n', 'C\r', 'D\u20ac'])