[REVIEW] Concatenate an empty and non-empty series

[marlenezw]

Hi! I updated the concat function to allow concatenating an empty series with a non-empty series. I also changed the test for concat_empty_series so dtypes for empty series are ignored. Looks like its passing tests and working on my end.

[GPUtester]

Please update the changelog in order to start CI tests.

View the gpuCI docs here.

[shwina]

@marlenezw to trigger CI, you'll need to update CHANGELOG.md and push that change. Add an entry with the PR number and title to it under cuDF 0.16 (bug fixes).

[rgsl888prabhu]

I am not sure if this scenario has been taken care

>>> import cudf
>>> sr1 = cudf.Series([1, 2, 3, 4])
>>> sr2 = cudf.Series()
>>> cudf.concat([sr1, sr2], axis=1, ignore_index=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/reshape.py", line 249, in concat
    df.index = None
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 572, in __setattr__
    object.__setattr__(self, key, col)
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 2522, in index
    new_length = len(value)
TypeError: object of type 'NoneType' has no len()

[marlenezw]

I am not sure if this scenario has been taken care

>>> import cudf
>>> sr1 = cudf.Series([1, 2, 3, 4])
>>> sr2 = cudf.Series()
>>> cudf.concat([sr1, sr2], axis=1, ignore_index=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/reshape.py", line 249, in concat
    df.index = None
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 572, in __setattr__
    object.__setattr__(self, key, col)
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 2522, in index
    new_length = len(value)
TypeError: object of type 'NoneType' has no len()

Oof, I'll make some changes to this! Thanks for the catch @rgsl888prabhu

[marlenezw]

Changing it to WIP while I make changes.

[codecov]

Codecov Report

Merging #6157 into branch-0.16 will increase coverage by 0.32%.
The diff coverage is 85.71%.

@@               Coverage Diff               @@
##           branch-0.16    #6157      +/-   ##
===============================================
+ Coverage        84.30%   84.63%   +0.32%     
===============================================
  Files               82       82              
  Lines            13745    14092     +347     
===============================================
+ Hits             11588    11927     +339     
- Misses            2157     2165       +8     

Impacted Files	Coverage Δ
python/cudf/cudf/core/reshape.py	89.06% <85.71%> (+0.21%)	⬆️
python/cudf/cudf/io/feather.py	100.00% <0.00%> (ø)
python/cudf/cudf/comm/serialize.py	0.00% <0.00%> (ø)
python/custreamz/custreamz/_version.py	0.00% <0.00%> (ø)
python/dask_cudf/dask_cudf/_version.py	0.00% <0.00%> (ø)
python/dask_cudf/dask_cudf/io/tests/test_csv.py	100.00% <0.00%> (ø)
python/dask_cudf/dask_cudf/io/tests/test_orc.py	100.00% <0.00%> (ø)
python/dask_cudf/dask_cudf/io/tests/test_json.py	100.00% <0.00%> (ø)
...ython/custreamz/custreamz/tests/test_dataframes.py	100.00% <0.00%> (ø)
...ython/dask_cudf/dask_cudf/io/tests/test_parquet.py	100.00% <0.00%> (ø)
... and 32 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 338968e...fe43053. Read the comment docs.

[marlenezw]

I added some changes that should hopefully have fixed this issue.

I am not sure if this scenario has been taken care

>>> import cudf
>>> sr1 = cudf.Series([1, 2, 3, 4])
>>> sr2 = cudf.Series()
>>> cudf.concat([sr1, sr2], axis=1, ignore_index=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/reshape.py", line 249, in concat
    df.index = None
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 572, in __setattr__
    object.__setattr__(self, key, col)
  File "/home/rgsl888/anaconda3/envs/cudf_dev/lib/python3.7/site-packages/cudf/core/dataframe.py", line 2522, in index
    new_length = len(value)
TypeError: object of type 'NoneType' has no len()

[cwharris]

lgtm 🎉