BUG: Changed .at to not set values that do not exist yet in a DataFrame #48323 #48542
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Does this overlap with #48362? If so I would recommend allowing @johannes-mueller to continue with that PR first |
In that PR, @johannes-mueller stated that if the behavior was made so that |
mroeschke
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| @@ -234,3 +237,9 @@ def test_at_categorical_integers(self): | |||
| for key in [0, 1]: | |||
| with pytest.raises(KeyError, match=str(key)): | |||
| df.at[key, key] | |||
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| def test_at_does_not_expand(self): | |||
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Maybe we should have two tests here, one for expansion in column axis and another one for expansion in index axis.
| expected = DataFrame( | ||
| [[10, 10], [0, 0], [0, 0]], | ||
| columns=MultiIndex.from_tuples([("a", 0), ("a", 1)]), | ||
| ) | ||
| tm.assert_frame_equal(df, expected) | ||
| with pytest.raises(TypeError, match=""): |
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Personally, I would put this into a separate test. One test for the happy path and one for the failing path. YMMV
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I don't want to split this because this isn't actually a test I created, but one I had to modify based on the code change, so I'd like to keep the change as small as I reasonably can.
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Well, fair enough.
Personally I am really reluctant to modify existing tests. So I would rather add a new one. YMMV
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From #48542, I think this needs deprecating. It is documented in the User Guide, so it would be a breaking change.
@rhshadrach How does the deprecation process work in Pandas? Is there something I should do, or does it just mean that someone else needs to announce the change before accepting my PR? (Note that my PR does include a change to the user guide to make it more accurate.) |
The behavior that is to be deprecated needs to raise a |
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This pull request is stale because it has been open for thirty days with no activity. Please update and respond to this comment if you're still interested in working on this. |
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Closing as stale. @srotondo - if you'd like to pick this back up and deprecate the behavior, we can reopen. |
doc/source/whatsnew/vX.X.X.rstfile if fixing a bug or adding a new feature.