Since 3.5 traceback.extract_tb() and traceback.extract_stack() return a list (actually list's subclass StackSummary) of FrameSummary objects instead of a list of tuples. FrameSummary is not fully compatible with tuple. One important incompatibility is in the comparing.

>>> import traceback
>>> traceback.extract_stack()[0] == ('<stdin>', 1, '<module>', '')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/serhiy/py/cpython-3.5/Lib/traceback.py", line 254, in __eq__
    return (self.filename == other.filename and
AttributeError: 'tuple' object has no attribute 'filename'

In general __eq__ shouldn't raise an exception. Issue25108 is needed to be fixed first for tests.

Here is a patch that restores compatibility.

An alternative solution would be to make FrameSummary a subclass of tuple (namedtuple).

Fixed patch and added tests.

Ping.

LGTM

+        self.assertEqual(f, tuple(f))
+        self.assertEqual(tuple(f), f)

It would be good to add a comment to explain why we test both variants, but it's not really important.

traceback_FrameSummary_equality_2.patch looks good to me, but I have the same remark than Berker (see the review).

LGTM too.

New changeset 2ecb7d4d9e0b by Serhiy Storchaka in branch '3.5':
Issue #25111: Fixed comparison of traceback.FrameSummary.
https://hg.python.org/cpython/rev/2ecb7d4d9e0b

New changeset f043182a81d7 by Serhiy Storchaka in branch 'default':
Issue #25111: Fixed comparison of traceback.FrameSummary.
https://hg.python.org/cpython/rev/f043182a81d7