Hello @jbrockmendel! Thanks for updating the PR.

• In the file pandas/compat/numpy/__init__.py, following are the PEP8 issues :

Line 63:17: W504 line break after binary operator

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

• In the file pandas/core/base.py, following are the PEP8 issues :

Line 398:27: W504 line break after binary operator

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

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

• In the file pandas/core/groupby/groupby.py, following are the PEP8 issues :

Line 581:21: W504 line break after binary operator
Line 1557:17: W504 line break after binary operator

• In the file pandas/core/groupby/grouper.py, following are the PEP8 issues :

Line 160:21: W504 line break after binary operator
Line 533:13: W504 line break after binary operator
Line 534:13: W504 line break after binary operator

• In the file pandas/core/groupby/ops.py, following are the PEP8 issues :

Line 524:17: W504 line break after binary operator

• In the file pandas/core/indexing.py, following are the PEP8 issues :

Line 1839:21: W504 line break after binary operator
Line 1850:29: W504 line break after binary operator

• In the file pandas/core/internals/concat.py, following are the PEP8 issues :

Line 187:25: W504 line break after binary operator

• In the file pandas/core/reshape/pivot.py, following are the PEP8 issues :

Line 143:13: W504 line break after binary operator

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

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

• In the file pandas/core/window.py, following are the PEP8 issues :

Line 101:17: W504 line break after binary operator
Line 104:17: W504 line break after binary operator

• In the file pandas/io/common.py, following are the PEP8 issues :

Line 433:13: W504 line break after binary operator

• There are no PEP8 issues in the file pandas/io/excel.py !

• There are no PEP8 issues in the file pandas/io/formats/style.py !

• In the file pandas/io/formats/terminal.py, following are the PEP8 issues :

Line 43:13: W504 line break after binary operator

• There are no PEP8 issues in the file pandas/io/json/normalize.py !

• In the file pandas/io/parsers.py, following are the PEP8 issues :

Line 3206:13: W504 line break after binary operator

• In the file pandas/io/pytables.py, following are the PEP8 issues :

Line 1807:21: W504 line break after binary operator

• In the file pandas/io/stata.py, following are the PEP8 issues :

Line 445:23: W504 line break after binary operator
Line 2072:25: W504 line break after binary operator

• There are no PEP8 issues in the file pandas/plotting/__init__.py !

Comment last updated on October 10, 2018 at 14:25 Hours UTC

Codecov Report

Merging #23073 into master will increase coverage by <.01%.
The diff coverage is 91.89%.

@@            Coverage Diff             @@
##           master   #23073      +/-   ##
==========================================
+ Coverage   92.19%    92.2%   +<.01%     
==========================================
  Files         169      169              
  Lines       50911    50916       +5     
==========================================
+ Hits        46939    46945       +6     
+ Misses       3972     3971       -1

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Nice change, but I think we expect and, or... after the line break, as we ignore W503 in the linting, and not W504. I don't have a preference, but I guess that's how it's in the rest of the code based on the linting setup.

as we ignore W503 in the linting, and not W504

OK, I was wondering why pep8speaks was complaining about those. I'm used to seeing the warnings in the other direction. Will update.

Just check the linting settings, you may want to look in more detail before changing.

this looks fine. Do we have a lint rule to flag the line-continuation? alt do it in lint.sh (this can be a followup).

@datapythonista you ok here? merge away.

I was checking again, and looks like indded our standard is to have the operator after the line break and not before. For example: https://github.com/pandas-dev/pandas/blob/master/pandas/core/series.py#L243

So, I think it makes sense to make the changes to this PR, unless we want to change the convention at this point, and change the others. I personally don't have a preference, and I don't know what's supposed to be the way to avoid both W503 and W504. But I think it makes sense to ignore just one of them, and be consistent in what we do.

Those are the cases where we're ignoring W503 right now:

./doc/make.py:103:30: W503 line break before binary operator
./doc/make.py:104:30: W503 line break before binary operator
./pandas/core/series.py:243:19: W503 line break before binary operator
./pandas/core/frame.py:420:15: W503 line break before binary operator
./pandas/core/generic.py:1257:17: W503 line break before binary operator
./pandas/core/generic.py:1269:17: W503 line break before binary operator
./pandas/core/strings.py:2115:32: W503 line break before binary operator
./pandas/core/strings.py:2119:33: W503 line break before binary operator
./pandas/core/arrays/integer.py:243:17: W503 line break before binary operator
./pandas/core/indexes/multi.py:837:21: W503 line break before binary operator
./pandas/core/indexes/base.py:3128:25: W503 line break before binary operator
./pandas/core/reshape/merge.py:972:21: W503 line break before binary operator
./pandas/core/reshape/merge.py:975:21: W503 line break before binary operator
./pandas/core/groupby/grouper.py:502:17: W503 line break before binary operator
./pandas/core/internals/blocks.py:2112:13: W503 line break before binary operator
./pandas/core/internals/blocks.py:2164:13: W503 line break before binary operator
./pandas/tests/indexes/datetimes/test_date_range.py:784:39: W503 line break before binary operator
./pandas/tests/extension/test_integer.py:31:13: W503 line break before binary operator
./pandas/tests/extension/test_integer.py:102:21: W503 line break before binary operator
./pandas/tests/extension/test_integer.py:103:21: W503 line break before binary operator
./pandas/tests/tseries/offsets/conftest.py:15:25: W503 line break before binary operator
./pandas/io/parsers.py:1717:12: W503 line break before binary operator
./pandas/io/sas/sas7bdat.py:307:17: W503 line break before binary operator
./pandas/io/formats/csvs.py:146:13: W503 line break before binary operator
./scripts/validate_docstrings.py:114:17: W503 line break before binary operator
./scripts/validate_docstrings.py:225:17: W503 line break before binary operator
./scripts/download_wheels.py:28:14: W503 line break before binary operator

@datapythonista hmm, that is not convention. though its possible we have both flavors of this as not checking before.

I didn't think this was our convention as much as what's suggested (though not enforced) by PEP8

https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator

I don't think we're at all consistent about it. My preference would certainly be to leave the before/after issue to a separate Issue/PR. But I'm happy to defer to @datapythonista if you think there's a Right Way To Do It.

Sorry, I just saw that flake8 does not validate W504 (the operator before the line break). I was assuming it didn't happen anywhere in the code before this PR, that's why I suggested to change it here.

I think it would be a good practice to follow the PEP8 recommendation (@WillAyd link) at some point, but that's surely for a different PR (and we'll have to wait for a newer version of flake8 that validates it, or use something else).

Happy to merge this, but I think it makes sense to wait for #23101, or pep8speaks may report invalid errors in new PRs .

Thanks @jbrockmendel, #23101 is merged, so the linting should complain about the binary operations now.