Issue 10242: unittest.assertItemsEqual makes too many assumptions.
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index dbf7aa2..f59c068 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -6,6 +6,7 @@
import pprint
import re
import warnings
+import collections
from . import result
from .util import (strclass, safe_repr, sorted_list_difference,
@@ -990,15 +991,13 @@
self.fail(self._formatMessage(msg, standardMsg))
- def assertItemsEqual(self, expected_seq, actual_seq, msg=None):
- """An unordered sequence / set specific comparison. It asserts that
- expected_seq and actual_seq contain the same elements. It is
- the equivalent of::
+ def assertCountEqual(self, expected_seq, actual_seq, msg=None):
+ """An unordered sequence specific comparison. It asserts that
+ expected_seq and actual_seq have the same element counts.
+ Equivalent to::
- self.assertEqual(sorted(expected_seq), sorted(actual_seq))
-
- Raises with an error message listing which elements of expected_seq
- are missing from actual_seq and vice versa if any.
+ self.assertEqual(Counter(iter(expected_seq)),
+ Counter(iter(actual_seq)))
Asserts that each element has the same count in both sequences.
Example:
@@ -1006,15 +1005,18 @@
- [0, 0, 1] and [0, 1] compare unequal.
"""
try:
- expected = sorted(expected_seq)
- actual = sorted(actual_seq)
+ expected = collections.Counter(iter(expected_seq))
+ actual = collections.Counter(iter(actual_seq))
except TypeError:
# Unsortable items (example: set(), complex(), ...)
expected = list(expected_seq)
actual = list(actual_seq)
missing, unexpected = unorderable_list_difference(expected, actual)
else:
- return self.assertSequenceEqual(expected, actual, msg=msg)
+ if expected == actual:
+ return
+ missing = list(expected - actual)
+ unexpected = list(actual - expected)
errors = []
if missing:
@@ -1027,6 +1029,9 @@
standardMsg = '\n'.join(errors)
self.fail(self._formatMessage(msg, standardMsg))
+ # Old name for assertCountEqual()
+ assertItemsEqual = assertCountEqual
+
def assertMultiLineEqual(self, first, second, msg=None):
"""Assert that two multi-line strings are equal."""
self.assertIsInstance(first, str, 'First argument is not a string')