diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/os.py | 4 | ||||
| -rw-r--r-- | Lib/test/test_os.py | 24 |
2 files changed, 27 insertions, 1 deletions
@@ -697,7 +697,9 @@ class _Environ(MutableMapping): raise KeyError(key) from None def __iter__(self): - for key in self._data: + # list() from dict object is an atomic operation + keys = list(self._data) + for key in keys: yield self.decodekey(key) def __len__(self): diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index d069270..49e5a37 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -835,6 +835,30 @@ class EnvironTests(mapping_tests.BasicTestMappingProtocol): self.assertIs(cm.exception.args[0], missing) self.assertTrue(cm.exception.__suppress_context__) + def _test_environ_iteration(self, collection): + iterator = iter(collection) + new_key = "__new_key__" + + next(iterator) # start iteration over os.environ.items + + # add a new key in os.environ mapping + os.environ[new_key] = "test_environ_iteration" + + try: + next(iterator) # force iteration over modified mapping + self.assertEqual(os.environ[new_key], "test_environ_iteration") + finally: + del os.environ[new_key] + + def test_iter_error_when_changing_os_environ(self): + self._test_environ_iteration(os.environ) + + def test_iter_error_when_changing_os_environ_items(self): + self._test_environ_iteration(os.environ.items()) + + def test_iter_error_when_changing_os_environ_values(self): + self._test_environ_iteration(os.environ.values()) + class WalkTests(unittest.TestCase): """Tests for os.walk().""" |