Implements delete() for Index

[itholic]

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Index.delete.html#pandas.Index.delete

>>> kidx = ks.Index([10, 10, 9, 8, 4, 2, 4, 4, 2, 2, 10, 10])
>>> kidx
Int64Index([10, 10, 9, 8, 4, 2, 4, 4, 2, 2, 10, 10], dtype='int64')

>>> kidx.delete(0)
Int64Index([10, 9, 8, 4, 2, 4, 4, 2, 2, 10, 10], dtype='int64')

>>> kidx.delete([0, 1, 2, 3, 10, 11])
Int64Index([4, 2, 4, 4, 2, 2], dtype='int64')

[itholic]

Now we have some problem with MultiIndex related with adding default index like below.

>>> sdf.show()
+---------------+
|__index_value__|
+---------------+
|         [a, x]|
|         [b, y]|
+---------------+

>>> sdf = _InternalFrame.attach_default_index(
...             sdf, default_index_type='distributed-sequence')
Traceback (most recent call last):
...
    raise TypeError("Unsupported type in conversion to Arrow: " + str(dt))
TypeError: Unsupported type in conversion to Arrow: StructType(List(StructField(__index_level_0__,StringType,false),StructField(__index_level_1__,StringType,false)))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
...
NotImplementedError: Invalid returnType with grouped map Pandas UDFs: StructType(List(StructField(__index_level_0__,LongType,true),StructField(__index_value__,StructType(List(StructField(__index_level_0__,StringType,false),StructField(__index_level_1__,StringType,false))),false))) is not supported

so explicitly doesn't support for now.

[codecov-io]

Codecov Report

Merging #1165 into master will increase coverage by 2.18%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1165      +/-   ##
==========================================
+ Coverage   92.83%   95.02%   +2.18%     
==========================================
  Files          34       34              
  Lines        7944     7961      +17     
==========================================
+ Hits         7375     7565     +190     
+ Misses        569      396     -173     

Impacted Files	Coverage Δ
databricks/koalas/missing/indexes.py	100.00% <ø> (ø)
databricks/koalas/indexes.py	97.16% <100.00%> (+0.09%)	⬆️
databricks/koalas/plot.py	94.28% <0.00%> (+0.95%)	⬆️
databricks/koalas/namespace.py	86.57% <0.00%> (+1.57%)	⬆️
databricks/koalas/frame.py	96.61% <0.00%> (+3.17%)	⬆️
databricks/conftest.py	96.22% <0.00%> (+7.54%)	⬆️
databricks/koalas/__init__.py	93.61% <0.00%> (+14.89%)	⬆️
databricks/koalas/usage_logging/usage_logger.py	100.00% <0.00%> (+50.00%)	⬆️
databricks/koalas/usage_logging/__init__.py	94.59% <0.00%> (+70.27%)	⬆️

---

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[HyukjinKwon]

Seems okay otherwise.

[HyukjinKwon]

@itholic, can you resolve conflicts?

[itholic]

@HyukjinKwon i did :)

[softagram-bot]

Softagram Impact Report for pull/1165 (head commit: 8f78dc8)

⚠️ Copy paste found

ℹ️ test_indexes.py: Copy paste fragment on line 32 shared with ../test_numpy_compat.py:

    def pdf(self):
        return pd.DataFrame({
            'a': [1, 2, 3, 4, 5, 6, 7, 8, 9],
            'b': [4, 5, 6, 3, 2, 1, 0, 0, 0],
        }, index=[0, 1, 3, 5, 6, 8, 9, 9, 9])...(truncated 101 chars)

ℹ️ indexes.py: Copy paste fragment inside the same file on lines 787, 1496:

            raise NotImplementedError(
                \"Doesn't support symmetric_difference between Index & MultiIndex for now\")

        sdf_self = self._kdf._s...(truncated 477 chars)

Now that you are on the file, it would be easier to pay back some tech. debt.

⭐ Change Overview

(Open in Softagram Desktop for full details)

📄 Full report

• Permalink: Full report for pull/1165

Impact Report explained. Give feedback on this report to support@softagram.com

[itholic]

@HyukjinKwon Yeah, I'm fixing those things you commented. Thanks for the remind :)

[HyukjinKwon]

@itholic looks you made a mistake during rebasing the branch ..

[itholic]

@HyukjinKwon Right. I'm fixing now 😭

[itholic]

I fixed but It seems that there is some problem in CI with conda.

[ueshin]

I'm taking a look at the conda build.

[ueshin]

@itholic The build must be fixed, maybe we should push another commit to cleanup the checks.

[itholic]

@ueshin

Thanks for the notice! I just pushed an empty commit :)

[ueshin]

I'm wondering how to restart the checks cleanly. haha

[itholic]

@ueshin

Oh, It seems that re-run the Actions is allowed for the repository owner in the Actions page.

(the screenshot was captured in my forked repository)

[codecov-commenter]

Codecov Report

Merging #1165 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1165      +/-   ##
==========================================
+ Coverage   94.17%   94.18%   +0.01%     
==========================================
  Files          38       38              
  Lines        8553     8570      +17     
==========================================
+ Hits         8055     8072      +17     
  Misses        498      498              

Impacted Files	Coverage Δ
databricks/koalas/missing/indexes.py	100.00% <ø> (ø)
databricks/koalas/indexes.py	97.13% <100.00%> (+0.09%)	⬆️

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[HyukjinKwon]

LGTM otherwise.

[itholic]

@HyukjinKwon Thanks!

[HyukjinKwon]

@itholic can you rebase this please?

[itholic]

@HyukjinKwon Yup, pending tests.