BUG: Concat with inner join and empty DataFrame #15397
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Codecov Report
@@ Coverage Diff @@
## master #15397 +/- ##
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- Coverage 90.42% 90.36% -0.06%
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Files 134 135 +1
Lines 49377 49438 +61
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+ Hits 44650 44677 +27
- Misses 4727 4761 +34
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doc/source/whatsnew/v0.20.0.txt
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| @@ -580,3 +580,5 @@ Bug Fixes | |||
| - Bug in ``Series.replace`` and ``DataFrame.replace`` which failed on empty replacement dicts (:issue:`15289`) | |||
| - Bug in ``pd.melt()`` where passing a tuple value for ``value_vars`` caused a ``TypeError`` (:issue:`15348`) | |||
| - Bug in ``.eval()`` which caused multiline evals to fail with local variables not on the first line (:issue:`15342`) | |||
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just an FYI, if you put changes in whatsnew NOT at the end (but in empty space that is left), then you won't get conflicts.
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ah i see. makes sense. thanks!
pandas/tests/tools/test_concat.py
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| @@ -1825,6 +1825,15 @@ def test_concat_bug_3602(self): | |||
| result = concat([df1, df2], axis=1) | |||
| assert_frame_equal(result, expected) | |||
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| def test_concat_bug_15328(self): | |||
| df_empty = pd.DataFrame() | |||
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put a comment here for the issue number (rather than in the test name) (try to be descriptive with that if possible)
pandas/tests/tools/test_concat.py
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| df_empty = pd.DataFrame() | ||
| df_a = pd.DataFrame({'a': [1, 2]}, index=[0, 1]) | ||
| result = pd.concat([df_empty, df_a], axis=1, join='inner') | ||
| self.assertTrue(result.empty) |
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construct the result frame and use assert_frame_equal
pandas/tests/tools/test_concat.py
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| self.assertTrue(result.empty) | ||
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| result = pd.concat([df_a, df_empty], axis=1, join='inner') | ||
| self.assertTrue(result.empty) |
pandas/tests/tools/test_concat.py
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| result = pd.concat([df_a, df_empty], axis=1, join='inner') | ||
| self.assertTrue(result.empty) | ||
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| def test_concat_series_axis1_same_names_ignore_index(self): |
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can you systematically tests the how=* here? (for the empty cases)
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sorry i'm not clear on what you mean here. could you clarify our point to something similar ?
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what I mean is something like:
for how, expected in [('inner', df_empty), ('outer', df_a), ('left', df_a), ('right', df_empty)]:
result = pd.concat([df_a, df_empty, axis=1, join=how)
assert_frame_equal(result, expected)
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oh haha. got it. thanks!
pandas/tests/tools/test_merge.py
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| df_empty = pd.DataFrame() | ||
| df_a = pd.DataFrame({'a': [1, 2]}, index=[0, 1]) | ||
| result = pd.merge(df_empty, df_a, left_index=True, right_index=True) | ||
| self.assertTrue(result.empty) |
| df_a = pd.DataFrame({'a': [1, 2]}, index=[0, 1], dtype='int64') | ||
| df_expected = pd.DataFrame({'a': []}, index=[], dtype='int64') | ||
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| for how, expected in [('inner', df_expected), ('outer', df_a)]: |
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right forgot this only accepts outer & inner
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thanks @abaldenko ! |
closes pandas-dev#15328 Author: abaldenko <[email protected]> Closes pandas-dev#15397 from abaldenko/concat_empty_dataframe and squashes the following commits: 47c8735 [abaldenko] BUG: Concat with inner join and empty DataFrame fc473b7 [abaldenko] BUG: Concat with inner join and empty DataFrame b86dcb6 [abaldenko] BUG: Concat with inner join and empty DataFrame
git diff upstream/master | flake8 --diff