BUG: Resolving fallback from skipna flag in groupby().sum()

[mukundm19]

• closes DataFrame.groupby().sum() treating Nan as 0.0 #20824
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

Issue #20824 found that a fallback was occuring when df.Groupby().sum() was called with the skipna flag. This was occurring because the _cython_agg_general function was not accepting the argument, which has now been fixed. The fallback still occurs with strings in the df, however this is a deeper issue stemming from the _aggregate() call in groupby/ops.py (line 572).

[codecov]

Codecov Report

Merging #26179 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #26179      +/-   ##
==========================================
- Coverage   91.98%   91.98%   -0.01%     
==========================================
  Files         175      175              
  Lines       52371    52371              
==========================================
- Hits        48175    48171       -4     
- Misses       4196     4200       +4

Flag	Coverage Δ
#multiple	90.53% <ø> (ø)	⬆️
#single	40.71% <ø> (-0.15%)	⬇️

Impacted Files	Coverage Δ
pandas/core/groupby/generic.py	89.02% <ø> (ø)	⬆️
pandas/io/gbq.py	78.94% <0%> (-10.53%)	⬇️
pandas/core/frame.py	96.9% <0%> (-0.12%)	⬇️

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[codecov]

Codecov Report

Merging #26179 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #26179      +/-   ##
==========================================
- Coverage   91.98%   91.98%   -0.01%     
==========================================
  Files         175      175              
  Lines       52371    52371              
==========================================
- Hits        48175    48171       -4     
- Misses       4196     4200       +4

Flag	Coverage Δ
#multiple	90.53% <ø> (ø)	⬆️
#single	40.71% <ø> (-0.15%)	⬇️

Impacted Files	Coverage Δ
pandas/core/groupby/generic.py	89.02% <ø> (ø)	⬆️
pandas/io/gbq.py	78.94% <0%> (-10.53%)	⬇️
pandas/core/frame.py	96.9% <0%> (-0.12%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[WillAyd]

Please add a test - should be the first part of any PR

[jreback]

needs a tests & whastnew

[jreback]

needs test; ping if you want to continue working.

[sireesha-m]

Hi folks,
How can one resolve this issue? I am using pandas 1.0.3 and experiencing the same issue, "skipna" is not being accepted by sum() function. The call below is failing with a similar error

cnt = df.groupby(groupby_cols).sum(skipna=False)[prop_cols]

_cython_agg_general() got an unexpected keyword argument 'skipna'