BUG: DataFrame bugs in ndarray assignments #53367
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mroeschke
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Any updates on this? |
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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. |
| @@ -432,6 +432,8 @@ Groupby/resample/rolling | |||
| Reshaping | |||
| ^^^^^^^^^ | |||
| - Bug in :func:`crosstab` when ``dropna=False`` would not keep ``np.nan`` in the result (:issue:`10772`) | |||
| - Bug in :meth:`BlockManager.insert` allows assignments for multiple-dimension ndarray into one column (:issue:`53366`) | |||
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BlockManager isn't user-facing. can you write this in terms of a DataFrame or Series method?
| elif ( | ||
| isinstance(value, np.ndarray) and value.ndim > 1 and self.columns.is_unique | ||
| ): | ||
| # TODO: a check for MultiIndex should be added |
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does the check on the next line not take care of this TODO?
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does the check on the next line not take care of this TODO?
No, the check here is just placeholder for further improvements, and the real check should be inserted between "isinstance" line and "_set_item" line. I did not figure out what and how checks for MultiIndex should be added so I skipped this. But I think the current PR is a mitigation covering and fixing frequently used scenes.
| return | ||
| # squeeze 2d ndarray to 1d if possible | ||
| # this keeps the backward compatibility | ||
| if np.ndim(value) == 2 and (1 in np.shape(value)): |
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can you use value.ndim and values.shape instead of the numpy methods
| @@ -3966,6 +3966,24 @@ def __setitem__(self, key, value): | |||
| ): | |||
| # Column to set is duplicated | |||
| self._setitem_array([key], value) | |||
| elif ( | |||
| isinstance(value, np.ndarray) and value.ndim > 1 and self.columns.is_unique | |||
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does it matter what 'key' is here?
| @@ -283,6 +283,11 @@ def test_constructor_cast_failure(self): | |||
| with pytest.raises(ValueError, match=msg): | |||
| df["test"] = np.ones((4, 2)) | |||
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| # this is not ok | |||
| msg = "Expected a 1D array, got an array with shape \\(4, 2, 3\\)" | |||
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this file is for constructor tests. can you put a dedicated test in tests/frame/indexing/test_setitem.py
| @@ -1401,7 +1401,7 @@ def insert(self, loc: int, item: Hashable, value: ArrayLike, refs=None) -> None: | |||
| # insert to the axis; this could possibly raise a TypeError | |||
| new_axis = self.items.insert(loc, item) | |||
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| if value.ndim == 2: | |||
| if value.ndim >= 2: | |||
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why is this needed?
A ndarray where dim >= 2 will bypass the check here, but still raise an Exception when accessing the DataFrame. For an example for this bug, see #53366
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Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen. |
DataFrame.__setitem__when >=3d ndarray is used #53366doc/source/whatsnew/v2.1.0.rstfile if fixing a bug or adding a new feature.