Interesting. Did you look at the code? It is here (that's the `==` operator you're complaining about):
https://github.com/python/cpython/blob/6afb730e2a8bf0b472b4c3157bcf5b44aa7e6d56/Lib/unittest/case.py#L970 The code does already analyze the length of the sequence You are right that collections.abc.Sequence (or its ancestors other than object) does not implement `__eq__`, so it would seem that the `==` operator would have to be replaced with a simple loop: ``` for x, y in zip(seq1, seq2): if x is not y and x != y: break else: return # They are all equal ``` Making that change would probably slow things down. (Note that the odd check "x is not y and x != y" is needed to keep the previous behavior regarding NaN and other objects that aren't equal to themselves.) One could also argue that the docstring warns about this issue: ``` For the purposes of this function, a valid ordered sequence type is one which can be indexed, has a length, and has an equality operator. ``` IOW, I think this ship has actually sailed. On Tue, Dec 22, 2020 at 10:56 AM Alan G. Isaac <alan.is...@gmail.com> wrote: > The following test fails because because `seq1 == seq2` returns a > (boolean) NumPy array > whenever either seq is a NumPy array. > > import unittest > import numpy as np > unittest.TestCase().assertSequenceEqual([1.,2.,3.], > np.array([1.,2.,3.])) > > I expected `unittest` to rely only on features of a > `collections.abc.Sequence`, > which based on https://docs.python.org/3/glossary.html#term-sequence, > I believe are satisfied by a NumPy array. Specifically, I see no > requirement > that a sequence implement __eq__ at all much less in any particular way. > > In short: a test named `assertSequenceEqual` should, I would think, > work for any sequence and therefore (based on the available documentation) > should not depend on the class-specific implementation of __eq__. > > Is that wrong? > > Thank you, Alan Isaac > _______________________________________________ > Python-Dev mailing list -- python-dev@python.org > To unsubscribe send an email to python-dev-le...@python.org > https://mail.python.org/mailman3/lists/python-dev.python.org/ > Message archived at > https://mail.python.org/archives/list/python-dev@python.org/message/6Z43SU2RPIHTRABYAXBOGRKWGTLIFJYK/ > Code of Conduct: http://python.org/psf/codeofconduct/ > -- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/>
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