Issue #26837: assertSequenceEqual() now correctly outputs non-stringified

differing items.  This affects assertListEqual() and assertTupleEqual().

Lib/unittest/case.py

@@ -689,7 +689,7 @@ class TestCase(object):
 
                 if item1 != item2:
                     differing += ('\nFirst differing element %d:\n%s\n%s\n' %
-                                 (i, item1, item2))
+                                 (i, safe_repr(item1), safe_repr(item2)))
                     break
             else:
                 if (len1 == len2 and seq_type is None and
@@ -702,7 +702,7 @@ class TestCase(object):
                              'elements.\n' % (seq_type_name, len1 - len2))
                 try:
                     differing += ('First extra element %d:\n%s\n' %
-                                  (len2, seq1[len2]))
+                                  (len2, safe_repr(seq1[len2])))
                 except (TypeError, IndexError, NotImplementedError):
                     differing += ('Unable to index element %d '
                                   'of first %s\n' % (len2, seq_type_name))
@@ -711,7 +711,7 @@ class TestCase(object):
                              'elements.\n' % (seq_type_name, len2 - len1))
                 try:
                     differing += ('First extra element %d:\n%s\n' %
-                                  (len1, seq2[len1]))
+                                  (len1, safe_repr(seq2[len1])))
                 except (TypeError, IndexError, NotImplementedError):
                     differing += ('Unable to index element %d '
                                   'of second %s\n' % (len1, seq_type_name))

Misc/NEWS

@@ -77,6 +77,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #26837: assertSequenceEqual() now correctly outputs non-stringified
+  differing items.  This affects assertListEqual() and assertTupleEqual().
+
 - Issue #26822: itemgetter, attrgetter and methodcaller objects no longer
   silently ignore keyword arguments.