Add automatic PEP8 checking to Travis

[tmylk]

A good example of this is sklearn

[souravsingh]

@tmylk I am interested in working on the issue.

[tmylk]

Great. Let's add pep8, (not autopep8) to travis.yml. We don't care about long lines so it should be ignored. See this for an example https://gist.github.com/MichaelCurrie/802ce28c993ff2dd632c

[markroxor]

@tmylk we can use pep8 but this will scan the complete repo and while working with the forks I have realised that there are way too many formatting issues. So the Travis build will fail until we rectify them all. So along with pep8 integration do you want that all the errors raised by pep8 should also be fixed under this PR?

[tmylk]

@markroxor Yes, an initial autopep8 is definitely a part of this PR.

[souravsingh]

I will be making a PR for autopep8 shortly

[tmylk]

Ping @souravsingh . Thanks for taking this up!

[souravsingh]

Apologies for not responding to the issue. I had to some commitments which came up suddenly and had to travel. I will finish up the issue once I get back( which should be by 28th)

[nishnik]

I think this issue is solved, isn't it ?

[tmylk]

@nishnik It was moved to #973 by @souravsingh
your help in incorporating the coala suggestions into the code would be very welcome

[tmylk]

Thanks to @SamriddhiJain adding Hanging Indent to pycodestyle in #1202, we can add a check to Travis.

Remaining items:

• Fix existing 237 hanging indent violations either by hand or by adding hanging indent to autopep8 package
• Fix other issues with autopep8
• Add automatic pycodestyle check to travis

pycodestyle --statistics -qq --ignore=E501,E731,E12,W503 . 


9       E101 indentation contains mixed spaces and tabs
11      E111 indentation is not a multiple of four
8       E114 indentation is not a multiple of four (comment)
4       E116 unexpected indentation (comment)
237     E134 Not hanging indent
13      E201 whitespace after '('
20      E202 whitespace before ']'
19      E203 whitespace before ':'
1       E221 multiple spaces before operator
2       E222 multiple spaces after operator
9       E225 missing whitespace around operator
41      E226 missing whitespace around arithmetic operator
86      E231 missing whitespace after ','
33      E241 multiple spaces after ','
67      E251 unexpected spaces around keyword / parameter equals
227     E261 at least two spaces before inline comment
5       E262 inline comment should start with '# '
100     E265 block comment should start with '# '
3       E266 too many leading '#' for block comment
1       E271 multiple spaces after keyword
3       E301 expected 1 blank line, found 0
79      E302 expected 2 blank lines, found 1
169     E303 too many blank lines (3)
35      E305 expected 2 blank lines after class or function definition, found 0
2       E306 expected 1 blank line before a nested definition, found 0
5       E401 multiple imports on one line
29      E402 module level import not at top of file
3       E502 the backslash is redundant between brackets
49      E701 multiple statements on one line (colon)
1       E703 statement ends with a semicolon
1       E711 comparison to None should be 'if cond is not None:'
2       E713 test for membership should be 'not in'
35      E722 do not use bare except'
2       E741 ambiguous variable name 'l'
8       W191 indentation contains tabs
37      W291 trailing whitespace
3       W292 no newline at end of file
43      W293 blank line contains whitespace
12      W391 blank line at end of file

[tmylk]

Automatic checks added in #1287. It doesn't include hanging indent yet.

Expecting it in a couple of months when PyCQA/pycodestyle#632 is merged in, and flake8 updates its' pycodestyle version.

[tmylk]

It seems that PyCQA/pycodestyle#632 is not moving. An alternative is to use yapf from google. That has a lot of indent flags

[menshikh-iv]

Done a long time ago (now PEP8 checked in the separate job in Travis)
https://github.com/RaRe-Technologies/gensim/blob/develop/.travis.yml#L15-L16