cvsanaly should move to Python 3

[cflewis]

Python 3 is where it's at... Python 2 is old and deprecated.

Running 2to3 indicates there's not all that much to do. Mostly changes from except Exception, e to except Exception as e and print being wrapped in parentheses.

2.6 should fully support Python 3 syntax. I've set up a Jenkins build which runs 2to3 across cvsanaly to see if it's compatible http://eisbox.soe.ucsc.edu/jenkins/job/cvsanaly_python3/. Once it builds clean, it will be.

[linzhp]

I like the idea of Python 3! Actually, it made me feel bad at the time I was learning Python that although the latest stable version was Python 3, I still needed to learn Python 2.6 because of the legacy code I needed to code with.

[cflewis]

Yeah, I agree.

I think the way to go is to begin writing code in Python 3 syntax, but not yet rely on Python 3-only stuff. This should maintain compatibility with Python 2.6. We can use Jenkins to make sure that we work across both 3 and 2.6/2.7.

[cflewis]

FWIW, I feel like I'm pretty close to solving this one. I've cleaned up some syntax (that was valid but ugly anyway) and changed from StringIO to BytesIO, which seems to help with Unicode compatibility.

[cflewis]

Giving up on this for the evening. Almost there.

Need to:

1. Figure out how to install setuptools for Python 3 on eisbox
2. Get repositoryhandler converted to Python 3 (seems like it's already OK).

However, there is also:
3. Change from MySQLdb to something else, like OurSQL.

This one might be tricky.

[cflewis]

I got setuptools on eisbox, and repositoryhandler has been fixed to be Python 3 compatible.

The Config is the last obvious problem with cvsanaly and Python3 . It just doesn't work in Python 3. If I do some hacks to try and get round the problem, it looks like it just stalls and doesn't do anything, perhaps indicating something else is broken too.