DEP: remove deprecated loffset and base args for resample and Grouper

[vamsi-verma-s]

• resolves on of the issues listed in STYLE fix pylint issues #48855
• All code checks passed.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

This is to enforce deprecation for loffset and base args which were deprecated in 1.1 (#31809).

removing loffset also resolves the pylint issue in #48855

---

Earlier Analysis:

There are two error raised by this check. Both in Resampler._apply_loffset for self.loffset .

loffset is an attribute of Grouper .

When .resample is called like below. A Resampler object is returned on a Grouper object rather than the Series (happens in get_resampler). Therefore, loffset attribute defined before access.

index = pd.date_range('1/1/2000', periods=9, freq='T')
series = pd.Series(range(9), index=index)
s = series.resample('3T')

pandas/pandas/core/resample.py

Lines 1577 to 1585 in 75d91c8

	def get_resampler(
	obj, kind=None, **kwds
	) -> DatetimeIndexResampler | PeriodIndexResampler | TimedeltaIndexResampler:
	"""
	Create a TimeGrouper and return our resampler.
	"""
	tg = TimeGrouper(**kwds)
	return tg._get_resampler(obj, kind=kind)

[MarcoGorelli]

thanks for your PR

looks like loffset is deprecated anyway https://github.com/pandas-dev/pandas/pull/31809/files

Do you want to just enforce the deprecation, so there's no need to ignore the check? There's a bunch of examples of how to do this, e.g. #49084

[vamsi-verma-s]

sure, it makes sense to enforce deprecation. i will go through the example and update.

[vamsi-verma-s]

Hi @MarcoGorelli,

looks like both base and loffset args were deprecated at the same time (#31809)
should I go ahead and look into enforcing deprecation for base as well?

[MarcoGorelli]

yeah, sure

[vamsi-verma-s]

not sure why flake8 is failing. I am unable to reproduce it on local

https://github.com/pandas-dev/pandas/actions/runs/3284846670/jobs/5411280291#step:4:68

[vamsi-verma-s]

Hi @MarcoGorelli , can you please take a look. I have made the changes to remove both loffset and base args.
I am unable to understand why flake8 is failing.

[MarcoGorelli]

 flake8..................................................................................................Failed
- hook id: flake8
- exit code: 1

pandas/tests/resample/test_deprecated.py:2:1: F401 'pandas.date_range' imported but unused

looks like date_range is just unused in that file, you just need to remove it from the imports

[vamsi-verma-s]

 flake8..................................................................................................Failed
- hook id: flake8
- exit code: 1

pandas/tests/resample/test_deprecated.py:2:1: F401 'pandas.date_range' imported but unused

looks like date_range is just unused in that file, you just need to remove it from the imports

it is used in one test here -

 pandas/tests/resample/test_deprecated.py ⨯                                                                                                                100% ██████████
---------------------------------------------------------- generated xml file: /workspaces/pandas/test-data.xml ----------------------------------------------------------
========================================================================== slowest 30 durations ==========================================================================
4.49s call     pandas/tests/resample/test_deprecated.py::test_interpolate_posargs_deprecation
0.03s setup    pandas/tests/resample/test_deprecated.py::test_interpolate_posargs_deprecation

(4 durations < 0.005s hidden.  Use -vv to show these durations.)
======================================================================== short test summary info =========================================================================
FAILED pandas/tests/resample/test_deprecated.py::test_pad_backfill_deprecation - NameError: name 'date_range' is not defined

Results (4.96s):
       1 passed
       1 failed
         - pandas/tests/resample/test_deprecated.py:35 test_pad_backfill_deprecation

I have installed pre-commit in the dev container on WSL. The commit is not rejected there.
I checked the version of flake8 installed, and it was also correct. Not able to replicate why it thinks date_range is not used.

[MarcoGorelli]

I think you just need to fetch upstream and then merge or rebase upstream/main, as the function where date_range is used has been removed

It's a good practice to reguarly fetch upstream and then merge or rebase

[vamsi-verma-s]

Thank you. I was looking at only the diff in this PR.

[vamsi-verma-s]

great. got to know this, my understanding was wrong on the diff-

This is a result of the type of diff we use on GitHub. We use git’s three dot diff, which is the difference between the latest commit on the HEAD branch and the last common ancestor commit with the base branch.

[vamsi-verma-s]

@MarcoGorelli Please review now.

[vamsi-verma-s]

Hi @MarcoGorelli , could you please review this.

[MarcoGorelli]

generally looks good (sorry for the delay, was away)

[MarcoGorelli]

there's a Removal of prior version deprecations/changes section

[vamsi-verma-s]

Thank you. I have moved the change note to deprecations section.

[MarcoGorelli]

Looks good to me, thanks @vamsi-verma-s

Leaving open for a bit in case others have comments