New post: Django Q objects with py3 and pytest #7
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@yanneves Can I get a merge? |
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Nice! |
| * `left` and `right` are not considered equal. | ||
| """ | ||
| assert type(left) is Q | ||
| assert type(right) is Q |
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assert isinstance(left, Q) and isinstance(right, Q) ??
https://stackoverflow.com/questions/1549801/differences-between-isinstance-and-type-in-python
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I did look at using isinstance and made the decision purely on the output that pytest gives:
================================= FAILURES =================================
________________________________ test_fails ________________________________
test_assert_q_equal.py:112: in test_fails
assert isinstance(a, Q)
E AssertionError: assert False
E + where False = isinstance('Q', Q)
_______________________________ test_fails2 ________________________________
test_assert_q_equal.py:116: in test_fails2
assert type(a) is Q
E AssertionError: assert <class 'str'> is Q
E + where <class 'str'> = type('Q')
==================== 2 failed, 8 passed in 0.07 seconds ====================
Using type means that pytest explains what the type was that was found in the output and I found this more helpful.
Do you think I should abandon that idea and go for isinstance for the flexibility?
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well you could just assert isinstance(a, Q), f'{a.__class__} is not subclass of Q'
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That's a much better idea than either of mine! I'll try it out and PR it in.
| Django's Q object does not implement ``__cmp__`` and neither does | ||
| ``Node`` which it extends (``Node`` is in the ``django.utils.tree`` module). | ||
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| Unfortunately, that means that comparison of Q objects that are equal fails. |
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you know, django does accept PR's
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My guess would be that do to this well could take quite a large amount of effort while the payoff would be small. In the original post I wrote about why I thought this would not be implemented in Django: http://jamescooke.info/comparing-django-q-objects.html#the-perfect-world-predicate-logic
What do you think?
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You could always argue that cmp could be done with str(self) == str(other) as a basic workaround like you have here
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That sounds like an idea - I might give it a go
| Django's Q object does not implement ``__cmp__`` and neither does | ||
| ``Node`` which it extends (``Node`` is in the ``django.utils.tree`` module). | ||
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| Unfortunately, that means that comparison of Q objects that are equal fails. |
There was a problem hiding this comment.
My guess would be that do to this well could take quite a large amount of effort while the payoff would be small. In the original post I wrote about why I thought this would not be implemented in Django: http://jamescooke.info/comparing-django-q-objects.html#the-perfect-world-predicate-logic
What do you think?
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@yanneves Thanks for reading. @adamchainz Thanks for reviewing. I'm going to merge and publish but I'll update the post based on your comments Adam |
Fixes #6
Adds new post comparing Q objects in Python 3 and links the two posts.