BUG: fix combine_first reorders columns #60791
Merged
+15
−3
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
yuanx749
force-pushed
the
combine_first
branch
from
d3e867e to
aefa296
Compare
mroeschke
reviewed
Jan 27, 2025
pandas/core/frame.py
Outdated
| @@ -8672,6 +8672,9 @@ def combine( | |||
| """ | |||
| other_idxlen = len(other.index) # save for compare | |||
|
|
|||
| # preserve column order | |||
| new_columns = self.columns.union(other.columns, sort=False) | |||
There was a problem hiding this comment.
Why does this need to be done here as opposed to where it was before?
There was a problem hiding this comment.
I put it before this, other = self.align(other) because align can change the column order of other, as it sorts keys lexicographically.
But I think it is better to do it where it was before, after the early return. I've updated it in the new commit.
mroeschke
approved these changes
Jan 27, 2025
|
Thanks @yuanx749 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
I changed an old test for the correct order of columns.
Note that the fix can also be done incombine, if it is preferred to be fixed there, sincecombine_firstcallscombine.With my previous fix, a test in "Future infer strings" failed, which is the corner case when
selfis an empty dataframe. I then made the fix incombine.doc/source/whatsnew/vX.X.X.rstfile if fixing a bug or adding a new feature.