BUG: Fix groupby sorting on ordered Categoricals (GH25871) #1
Conversation
This file contains hidden or 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
As documented in pandas-dev#25871, groupby() on an ordered Categorical messes up category order when 'observed=True' is specified. Specifically, group labels will be ordered by first occurrence (as for an unordered Categorical), but grouped aggregation results will retain the Categorical's order. The fix is a modified subset of pandas-dev#25173, which fixes a related case, but has not been merged yet.
Testing all combinations of: - ordered vs. unordered grouping column - 'observed' True vs. False - 'sort' True vs. False In all cases, result group ordering must be correct. The test is built such that the result index labels are equal to aggregation results if all goes well (except for the one unobserved category)
kpflugshaupt
added a commit
that referenced
this pull request
Mar 28, 2019
This reverts commit b265349.
kpflugshaupt
added a commit
that referenced
this pull request
Mar 28, 2019
* BUG: Fix groupby sorting on ordered Categoricals (GH25871) (#1) * BUG: Fix groupby on ordered Categoricals (GH25871) As documented in pandas-dev#25871, groupby() on an ordered Categorical messes up category order when 'observed=True' is specified. Specifically, group labels will be ordered by first occurrence (as for an unordered Categorical), but grouped aggregation results will retain the Categorical's order. The fix is a modified subset of pandas-dev#25173, which fixes a related case, but has not been merged yet. * BUG: Fix groupby on ordered Categoricals (GH25871) * new test * Fix groupby on ordered Categoricals (GH25871) Testing all combinations of: - ordered vs. unordered grouping column - 'observed' True vs. False - 'sort' True vs. False In all cases, result group ordering must be correct. The test is built such that the result index labels are equal to aggregation results if all goes well (except for the one unobserved category) * Revert "BUG: Fix groupby sorting on ordered Categoricals (GH25871) (#1)" This reverts commit b265349.
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.
As documented in pandas-dev#25871, groupby() on an ordered Categorical messes up category order when 'observed=True' is specified.
Specifically, group labels will be ordered by first occurrence (as for an unordered Categorical), but grouped aggregation results will retain the Categorical's order.
The fix is a modified subset of pandas-dev#25173, which fixes a related case, but has not been merged yet.
git diff upstream/master -u -- "*.py" | flake8 --diff