I forked this off Guilhermes branch, which is the main one. He wrote the majority of the code
Making code strictly PEP8 compliant for PEP8's sake isn't cool. e.g. Using URL shorteners, or adjusting comments to wrap because they go barely over some arbritary 80-char width by one character makes readability worse. But this isn't my project, so my opinons on this isn't entierly valid.
The commit about making it work on MySQL seems perfectly valid to me, though.
I like PEP8 but I don't like be so strict. I don't like function headers in two or more lines for example, neither care about the urls.py... Almost all your changes are valid, but I made some comments about my personal preferences that, IMHO, helps the readability.
When PEP8 harm too much the readability, I avoid it.
All your changes are ok, but if you like my suggestions could you change it for us? Afterwards I can give a look as well and change what I don't like and try put in some form that fit in PEP8 too. That not mean my way is the best one, if you disagree with me in some coding style just give your opinion so we can try reach a consensus.