Until last fall I was working in python 2 (due to some limitations at work) and was very happy to have the Syntastic module in my Vim configuration to flag error each time I save a python file. This was great, especially after writing in C/C++ for years where there is no official standard format and really poor tools to enforce coding standards.
Then, last fall when I started on Django, I made the decision to move to Python 3. I quickly discovered that pylint is very version-dependent and running the python2.7 version of pylint against Python3 code was not going to work.
I wasn’t particularly familiar with virtualenv at the time, so I gave up and moved on with other things at the time. I finally got back to fixing this and thus getting pylint and flake8 running again on my code.
Syntastic
I won’t cover the details of how to install Syntastic as it depends on how you manage your plugins in Vim and is well documented. I will only point out here that Syntastic isn’t a checker by itself, it’s merely a plugin to run various checkers for you directly in Vim. It run checkers for many languages, but I’m only using it for Python currently as the C code I use for work is so ugly that it will never pass.
Switching versions
The key to getting pylint to run against different versions of python is to not install pylint on a global level, but rather to install it in each virtualenv. This seems obvious now that I’m more familiar with virtualenv, but I’ll admit it wasn’t at the time I first ran into the problem.
The other key to getting this to work is to only initiate Vim from inside the virtualenv. This hampers my overall workflow a bit, as I tend to have gVim up and running for the long-term and just add files in new tabs as I go. To get pylint to work properly, I’ll need to restart Vim when I switch python versions (at a minimum). This shouldn’t be too much of a problem, however, as I’m doing less and less python2x coding these days.
Coding Style Thoughts
As I beat my head against horrible C code on a daily basis at work, I find myself appreciating more-and-more the idea of PEP-8 and having good tools for coding style enforcement. While I frequently find some of the rules odd (two spaces here, but only one space there?) I really find it comforting to have a tool which runs, and runs quickly, to keep the code looking consistent. Now if I could only get that kind of tool for C…….
