Issue #10180: Pickling file objects is now explicitly forbidden, since
unpickling them produced nonsensical results.
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 680e36d..91dd803 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -30,6 +30,7 @@
import signal
import errno
import warnings
+import pickle
from itertools import cycle, count
from collections import deque
from test import support
@@ -2566,6 +2567,23 @@
self._check_warn_on_dealloc_fd("r")
+ def test_pickling(self):
+ # Pickling file objects is forbidden
+ for kwargs in [
+ {"mode": "w"},
+ {"mode": "wb"},
+ {"mode": "wb", "buffering": 0},
+ {"mode": "r"},
+ {"mode": "rb"},
+ {"mode": "rb", "buffering": 0},
+ {"mode": "w+"},
+ {"mode": "w+b"},
+ {"mode": "w+b", "buffering": 0},
+ ]:
+ for protocol in range(pickle.HIGHEST_PROTOCOL + 1):
+ with self.open(support.TESTFN, **kwargs) as f:
+ self.assertRaises(TypeError, pickle.dumps, f, protocol)
+
class CMiscIOTest(MiscIOTest):
io = io