BUG: Fix bug with symmetric difference of two equal MultiIndexes GH12490 #13504
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Current coverage is 84.34%@@ master #13504 diff @@
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Files 138 138
Lines 51107 51122 +15
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+ Hits 43103 43117 +14
- Misses 8004 8005 +1
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| result_name = result_name_update | ||
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| if self.equals(other): | ||
| return MultiIndex(levels=[[]] * self.nlevels, |
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make a constructor that creates an empty MultiIndex._create_as_empty() and just call here for both of these
jreback
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| @@ -527,3 +527,5 @@ Bug Fixes | |||
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| - Bug in ``Categorical.remove_unused_categories()`` changes ``.codes`` dtype to platform int (:issue:`13261`) | |||
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put your whatsnew higher up (in an empty space in Bug Fixes) this way you dont have conflicts
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If Travis passes again I think I got all your comments fixed
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| return MultiIndex(levels=[[]] * nlevels, | ||
| labels=[[]] * nlevels, | ||
| names=names, verify_integrity=verify_integrity) | ||
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note that this is internal. add a Parameters section
| return self._create_as_empty(names=result_name) | ||
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| difference = sorted(set((self.difference(other)). | ||
| union(other.difference(self)))) |
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Just a comment:
This sorting breaks with mixed-int values (same issue as in #13432). I suppose this line may be safely replaced with the code from PR #13514, slightly changed, namely:
this = self._get_unique_index()
other = other._get_unique_index()
indexer = this.get_indexer(other)
# {this} minus {other}
common_indexer = indexer.take((indexer != -1).nonzero()[0])
left_indexer = np.setdiff1d(np.arange(this.size), common_indexer,
assume_unique=True)
left_diff = this.values.take(left_indexer)
# {other} minus {this}
right_indexer = (indexer == -1).nonzero()[0]
right_diff = other.values.take(right_indexer)
the_diff = _concat._concat_compat([left_diff, right_diff])Then if the_diff is empty, an empty MI should be returned, otherwise:
return self._shallow_copy(the_diff, names=result_name).sortlevel()(In comparison to Index.symmetric_difference sorting is postponed until the end.)
Similar change may be applied to MultiIndex.difference, I guess.
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can you rebase / update? |
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closing, but pls reopen / comment if you can continue |
git diff upstream/master | flake8 --diffFixes a bug where the symmetric difference of two equal MultiIndexes would raise a TypeError. MultiIndex used to use the
Index.symmetric_difference. With this PR it it's own implementation that is more likeMultiIndex.difference.