Document our code_style_guide rules for python

[jwnimmer-tri]

We need to document our code_style_guide.rst rules for python code. We have C++, Java, and MATLAB rules now, but not python.

For the record, in #1741 we choose googlestyle for C++ but didn't appear to discuss other languages. I don't think there's anything else major we've missed, though.

[jwnimmer-tri]

For starters, I think its obvious to elect PEP-8 as the basic rules. We can tack on more beyond that if we start to care.

Probably also worth documenting how to run the pep8 style-checker tool.

[liangfok]

+1 for PEP-8.

[jamiesnape]

Would you like me to run flake8 or pylint on PR's?

[jamiesnape]

The Google style guide for Python seems reasonable. As far as I can tell, it is PEP8 plus a few other things.

[jwnimmer-tri]

Would you like me to run flake8 or pylint on PR's?

Possibly in the future, but for now I'd suggest that someone to test it locally and in integrate into drake-distro first, and then toss it into jenkins. Also there's not that much python code in Drake, so probably not a high priority.

[david-german-tri]

Sounds reasonable to me.

[rdeits]

FYI: the pep8 package has been renamed to the more-readable pycodestyle package going forward.

[jamiesnape]

There is also yapf to autoformat Python files in the same spirit as clang-format.

[jwnimmer-tri]

Let me try kicking this over to @david-german-tri, since I'm not foresee-ably going to work on it, ever.

[david-german-tri]

I'm never going to work on this either. Dropping it to the backlog.

[jwnimmer-tri]

I wonder if @rpoyner-tri would be interested in taking a stab at this, and perhaps relating it to TRI python style?

[rpoyner-tri]

Sure.