API: Disallow dict as agg parameter during groupby

[gfyoung]

Grouped, rolled, and resample Series / DataFrames will now disallow dicts / nested dicts respectively
as parameters to aggregation (was deprecated before).

xref #15931.

[pep8speaks]

Hello @gfyoung! Thanks for submitting the PR.

• There are no PEP8 issues in the file pandas/core/base.py !

• There are no PEP8 issues in the file pandas/core/groupby/generic.py !

• There are no PEP8 issues in the file pandas/tests/groupby/aggregate/test_aggregate.py !

• There are no PEP8 issues in the file pandas/tests/groupby/aggregate/test_other.py !

• There are no PEP8 issues in the file pandas/tests/groupby/test_groupby.py !

• There are no PEP8 issues in the file pandas/tests/test_resample.py !

• There are no PEP8 issues in the file pandas/tests/test_window.py !

[codecov]

Codecov Report

Merging #23393 into master will decrease coverage by 0.03%.
The diff coverage is 87.5%.

@@            Coverage Diff             @@
##           master   #23393      +/-   ##
==========================================
- Coverage   92.16%   92.13%   -0.04%     
==========================================
  Files         166      166              
  Lines       51224    51224              
==========================================
- Hits        47212    47194      -18     
- Misses       4012     4030      +18

Flag	Coverage Δ
#multiple	90.56% <87.5%> (-0.04%)	⬇️
#single	42.22% <0%> (-0.01%)	⬇️

Impacted Files	Coverage Δ
pandas/core/groupby/generic.py	86.77% <100%> (-0.27%)	⬇️
pandas/core/base.py	93.8% <83.33%> (-3.81%)	⬇️

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[gfyoung]

@jreback : Rebased and green. PTAL.

[jreback]

@jorisvandenbossche @TomAugspurger any objections. even though there is not a great soln to replace this, it is time.

[TomAugspurger]

I think this shouldn’t be enforced until we have a replacement in place. Rather we should update the warning to show the new style once that’s implemented, and give people a release to update.

[jorisvandenbossche]

Yes, IMO we should first work on the ideas discussed in #18366.

I am going to try to find some time for that the coming month, but other people looking at it is certainly welcome.

[gfyoung]

Ah, thanks for reminding me about #18366, in which case, I do agree that this error should wait...

Where does 0.25 fit into deprecation removals though? (I see only targets for 1.0 in #6581)

[TomAugspurger]

AFAIK, the current plan is to deprecate everything in 0.24, not remove anything in 0.25, and have 1.0 be backwards-compat with 0.25 aside from the removals of deprecated features. The idea is for people to upgrade 0.25, fix warnings, and then get on 1.0 relatively easily.

…

On Sun, Oct 28, 2018 at 2:08 PM gfyoung ***@***.***> wrote: Ah, thanks for reminding me about #18366 <#18366>, in which case, I do agree that this error should wait... Where does 0.25 fit into deprecation removals though? (I see only targets for 1.0) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#23393 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABQHIkrqOAzXvD6b9-poqamTFFXHLAOIks5upgC8gaJpZM4X9vAu> .

[gfyoung]

Gotcha. In that case, I'll move this deprecation removal to 1.0.