Python 3

[mnot]

I looked into what it would take to convert to 3, since 2 is no longer supported.

The short list is:

• Run 2to3 -wn .
• Add #!/usr/bin/env python3 where appropriate
• change rfc822 to email.utils in src/feedvalidator/validators.py
• change new.instgancemethod to types.methodType in src/validtest.py
• explicitly set encoding for the XML file when opening in src/validtest.py's getDescription
• change UnicodeError to UnicodeDecodeError or UnicodeEncodeError as appropriate
• explicitly convert the result of .encode('idna') back to a string (various places)
• in src/tests/testXmlEncoding.py, change many things to binary literals
• avoid using xmlEncoding.asUTF8 in src/feedvalidator/__init__.py

Where I got stuck was in how the code uses object inheritance so extensively; thanks to the switch to new-style objects, this doesn't work any more, and the trivial fix (removing things like validatorBase to avoid duplication) seems to mess with the processing model, causing many errors. E.g.,

TypeError: Cannot create a consistent method resolution
order (MRO) for bases text, rfc2396_full

Fixing this looks pretty invasive, and I'm not confident enough in this codebase to make the necessary changes. If someone is interested in helping out, I can do a PR for the things above and work with them on the solution.

[rubys]

Go for it! I will try to answer any questions, and may even make some fixes.