ENH: Implement dict-like support for rename and set_names in MultiIndex #38126

phofl · 2020-11-28T01:23:22Z

closes API: Allow MultiIndex.rename() to accept a dict as an argument #20421
tests added / passed
passes black pandas
passes git diff upstream/master -u -- "*.py" | flake8 --diff
whatsnew entry

I tried my hand in adding support for dict-like renamings for MultiIndexes. This seemed as the most straight forward way to me, because we do not have to add complex logic as long as we can cast the dict-like objects to regular configurations.

We probably must add a docstring to MultiIndex.rename now?

pandas/core/indexes/base.py

jreback · 2020-11-28T18:15:19Z

pandas/core/indexes/base.py

@@ -1366,6 +1367,12 @@ def set_names(self, names, level=None, inplace: bool = False):
                    ( 'cobra', 2018),
                    ( 'cobra', 2019)],
                   names=['species', 'year'])
+        >>> idx.set_names({'kind': 'snake'})


add a comment on this example (skip a line)

pandas/core/indexes/base.py

jreback · 2020-11-28T18:15:45Z

pandas/core/indexes/base.py

@@ -1385,6 +1398,12 @@ def set_names(self, names, level=None, inplace: bool = False):
            idx = self
        else:
            idx = self._shallow_copy()
+
+        if isinstance(self, ABCMultiIndex) and is_dict_like(names):


add a comment on what this condition is doing?

jreback · 2020-11-28T18:17:01Z

pandas/core/indexes/base.py

@@ -1385,6 +1398,12 @@ def set_names(self, names, level=None, inplace: bool = False):
            idx = self
        else:
            idx = self._shallow_copy()
+
+        if isinstance(self, ABCMultiIndex) and is_dict_like(names):
+            level = Index(self.names).get_indexer_for(names)


can you not just iterate over these to grab the levels? (and use get_level_values)?

Yep, thx. Thats way better.

List comprehensions would be an option too, but would have to loop twice. Would prefer ist this way

jreback

see comments

jreback · 2020-11-29T18:12:36Z

pandas/core/indexes/base.py

@@ -1376,6 +1393,12 @@ def set_names(self, names, level=None, inplace: bool = False):
        if not is_list_like(names) and level is None and self.nlevels > 1:
            raise TypeError("Must pass list-like as `names`.")

+        if is_dict_like(names) and not isinstance(self, ABCMultiIndex):


all of these conditions can be if/elif

Wanted to be consistent with the existing conditions, changed them to elif

jreback · 2020-11-29T18:13:08Z

pandas/core/indexes/base.py

+
+        if is_dict_like(names) and level is not None:
+            raise TypeError("Can not pass level when passing dict-like as `names`.")
+


doesn't this hit a dict-like names?

Yikes, yes you are right. have not though about dict like names. Removed this

jreback · 2020-11-29T18:14:18Z

pandas/core/indexes/base.py

+        if isinstance(self, ABCMultiIndex) and is_dict_like(names):
+            # Transform dict to list of new names and corresponding levels
+            level, names_adjusted = [], []
+            for i, name in enumerate(self.names):


see my comment above i think this condition needs to be on L1402

Moved it up a bit and added level is None

jreback · 2020-12-02T02:15:26Z

cc @Dr-Irv if you'd have a look. this is api you were expecting (from the OP)?

Dr-Irv

Needs tests for the basic use case in the original issue.

pandas/tests/indexes/multi/test_names.py

Dr-Irv · 2020-12-02T14:53:44Z

cc @Dr-Irv if you'd have a look. this is api you were expecting (from the OP)?

Yes, that is the API. I didn't check the implementation, but the tests should reflect the "normal" use case of having a MultiIndex with names that are different for each level, and you want to change one or two of the names. Also, should check that behavior is consistent with DataFrame.rename() if a name in the dict argument is not one of the level names - I'm not sure what we do in DataFrame.rename() if that is the case.

phofl · 2020-12-02T22:33:41Z

@Dr-Irv

Concerning missing names: I have oriented me on df.rename, as you also suggested. df.rename does nothing for missing index elements or column names.

Additionally for duplicates: Same holds true here. Is also done like df.rename. It produces duplicates if we have the same name twice in the original and it also produces duplicates if the targets already exist.

Dr-Irv

LGTM. Final approval rests with @jreback

…421_before_merge � Conflicts: � doc/source/whatsnew/v1.2.0.rst

…421_before_merge � Conflicts: � doc/source/whatsnew/v1.3.0.rst

phofl · 2021-01-03T21:43:05Z

ping

jreback · 2021-01-04T03:59:14Z

pandas/core/indexes/base.py

+            If the index is a MultiIndex and names is not dict-like, level(s) to set
+            (None for all levels). Otherwise level must be None.
+
+            .. versionchanged:: 1.2.0


jreback · 2021-01-04T03:59:38Z

pandas/core/indexes/base.py

@@ -1425,16 +1433,37 @@ def set_names(self, names, level=None, inplace: bool = False):
                    ( 'cobra', 2018),
                    ( 'cobra', 2019)],
                   names=['species', 'year'])
+
+        When renaming levels through a dictionary no level can't be passed.


When renaming levels with a dict, levels can not be passed.

pandas/tests/indexes/multi/test_names.py

jreback

comment, ping on green

jreback · 2021-01-04T13:43:34Z

pandas/core/indexes/base.py

            Name(s) to set.
+
+            .. versionchanged:: 1.2.0


change to 1.3

phofl · 2021-01-04T16:58:57Z

@jreback green

jreback · 2021-01-04T18:55:47Z

thanks @phofl

…ex (pandas-dev#38126)

phofl added 3 commits November 28, 2020 02:17

ENH: Implement dict-like support for rename and set_names in MultiIndex

d95308f

Run black

d1ec051

Move import

da475c7

phofl added the MultiIndex label Nov 28, 2020

Fix doc example

00c0134

jreback reviewed Nov 28, 2020

View reviewed changes

jreback requested changes Nov 28, 2020

View reviewed changes

phofl added 3 commits November 29, 2020 00:23

Add comments

de76243

Use for loop

dbfce8d

Use regular loop

0f4d773

jreback requested changes Nov 29, 2020

View reviewed changes

Remove wrong condition

a56a04b

Dr-Irv requested changes Dec 2, 2020

View reviewed changes

pandas/tests/indexes/multi/test_names.py Show resolved Hide resolved

Add tests

dd49505

Rename test

b346427

Dr-Irv approved these changes Dec 2, 2020

View reviewed changes

phofl added 3 commits December 11, 2020 18:40

Merge branch 'master' of https://github.com/pandas-dev/pandas into 20…

2df5ccf

…421_before_merge � Conflicts: � doc/source/whatsnew/v1.2.0.rst

Move whatsnew

02c7909

Merge branch 'master' of https://github.com/pandas-dev/pandas into 20…

ad5fe75

…421_before_merge � Conflicts: � doc/source/whatsnew/v1.3.0.rst

jreback requested changes Jan 4, 2021

View reviewed changes

phofl added 2 commits January 4, 2021 13:23

Adjust doc

0f5f6e1

Add test and add condition

b4767d2

jreback added this to the 1.3 milestone Jan 4, 2021

jreback added the Enhancement label Jan 4, 2021

jreback requested changes Jan 4, 2021

View reviewed changes

Change number

c9f7264

jreback approved these changes Jan 4, 2021

View reviewed changes

jreback merged commit e4614cb into pandas-dev:master Jan 4, 2021

phofl deleted the 20421 branch January 4, 2021 18:56

luckyvs1 pushed a commit to luckyvs1/pandas that referenced this pull request Jan 20, 2021

ENH: Implement dict-like support for rename and set_names in MultiInd…

0ce0f6b

…ex (pandas-dev#38126)

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

ENH: Implement dict-like support for rename and set_names in MultiIndex #38126

ENH: Implement dict-like support for rename and set_names in MultiIndex #38126

phofl commented Nov 28, 2020

jreback Nov 28, 2020

phofl Nov 28, 2020 •

edited

Loading

jreback Nov 28, 2020

phofl Nov 28, 2020

jreback Nov 28, 2020

phofl Nov 28, 2020

jreback left a comment

jreback Nov 29, 2020

phofl Nov 29, 2020

jreback Nov 29, 2020

phofl Nov 29, 2020

jreback Nov 29, 2020

phofl Nov 29, 2020

jreback commented Dec 2, 2020

Dr-Irv left a comment

Dr-Irv commented Dec 2, 2020

phofl commented Dec 2, 2020

Dr-Irv left a comment

phofl commented Jan 3, 2021

jreback Jan 4, 2021

phofl Jan 4, 2021

jreback Jan 4, 2021

phofl Jan 4, 2021

jreback left a comment

jreback Jan 4, 2021

phofl Jan 4, 2021

phofl Jan 4, 2021

phofl commented Jan 4, 2021

jreback commented Jan 4, 2021


		if is_dict_like(names) and level is not None:
		raise TypeError("Can not pass level when passing dict-like as `names`.")

ENH: Implement dict-like support for rename and set_names in MultiIndex #38126

ENH: Implement dict-like support for rename and set_names in MultiIndex #38126

Conversation

phofl commented Nov 28, 2020

Choose a reason for hiding this comment

phofl Nov 28, 2020 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

jreback left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

jreback commented Dec 2, 2020

Dr-Irv left a comment

Choose a reason for hiding this comment

Dr-Irv commented Dec 2, 2020

phofl commented Dec 2, 2020

Dr-Irv left a comment

Choose a reason for hiding this comment

phofl commented Jan 3, 2021

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

jreback left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

phofl commented Jan 4, 2021

jreback commented Jan 4, 2021

phofl Nov 28, 2020 •

edited

Loading