Deprecate suffixes in merge producing duplicate columns #40991
Merged
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
phofl
added
Deprecate
mroeschke
approved these changes
Apr 20, 2021
jreback
requested changes
Apr 20, 2021
| left = DataFrame({"a": [1, 2, 3], "b": 1, "b_x": 2}) | ||
| right = DataFrame({"a": [1, 2, 3], "b": 2}) | ||
| with tm.assert_produces_warning(FutureWarning): | ||
| merge(left, right, on="a") |
There was a problem hiding this comment.
can you assert the results here
There was a problem hiding this comment.
Done and added another test
| left = DataFrame([[1, 1, 1], [2, 2, 2]], columns=["a", "b", "b"]) | ||
| right = DataFrame({"a": [1, 3], "b": 2}) | ||
| result = merge(left, right, on="a") | ||
| expected = DataFrame([[1, 1, 1, 2]], columns=["a", "b_x", "b_x", "b_y"]) |
There was a problem hiding this comment.
is this the expected result?
There was a problem hiding this comment.
Yes, I wanted to avoid raising when we already get duplicate columns as input, because the collisions in this case are not caused by the suffixes
There was a problem hiding this comment.
kk, can you add a comment to this effect
mroeschke
approved these changes
Apr 20, 2021
jreback
approved these changes
Apr 20, 2021
|
thanks @phofl |
yeshsurya
pushed a commit
to yeshsurya/pandas
that referenced
this pull request
Apr 21, 2021
yeshsurya
pushed a commit
to yeshsurya/pandas
that referenced
this pull request
May 6, 2021
JulianWgs
pushed a commit
to JulianWgs/pandas
that referenced
this pull request
Jul 3, 2021
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Outdated suggestions cannot be applied.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 think we should not allow these column collisions at all. Hence deprecating and raising in 2.0
Alternative here would be to add an
errorskeyword to the merge and join functions as @simonjayhawkins mentioned in the op.