support python 3

[snarfed]

i believe the long pole here is a few indirect dependencies via oauth-dropins that don't support python 3. google-api-python-client? others? need to audit and come up with the complete list.

[kylewm]

google-api-python-client claims to support python 3!

[snarfed]

ooh! now if only they'd cut a release. :P googleapis/google-api-python-client#421

[snarfed]

https://caniusepython3.com/project/granary claims we're only blocked on gdata and python-tumblpy.

[snarfed]

...and tumblpy actually claims it supports python 3!

gdata definitely does not: google/gdata-python-client#29 (also google/gdata-python-client#47)

here's a gdata fork that supposedly does: https://github.com/dvska/gdata-python3

[snarfed]

also, app engine standard is still python 2 only (and will probably always be), so i'll need to maintain python 2 compatibility. six and future are the two libraries for that i'm familiar with. not sure which is better.

[snarfed]

hrm, mox is also python 2 only: glasser/pymox#45

here's a fork that attempts python 3 compatibility:
https://github.com/e0ne/pymox/tree/python3
https://pypi.python.org/pypi/mox3

assuming i use six or future, i could install both mox versions and test with both python versions, respectively.

otherwise i could theoretically ship python 3 support while keeping the tests python 2 only, but that's not ideal.

[snarfed]

sounds like future is preferred to six. requires more recent versions of python 2 and, but it's more featureful and results in less crufty code.

• https://docs.python.org/3/howto/pyporting.html#drop-support-for-python-2-6-and-older
• http://python-future.org/faq.html#what-is-the-relationship-between-future-and-six
• https://stackoverflow.com/questions/42110826/writing-cross-compatible-python-2-3-difference-between-future-six-and-fut

[snarfed]

note to myself, how i set up the virtualenv to use my local source clone of python-future:

cd l
foreach d (_dummy_thread _markupbase _thread builtins copyreg future html http libfuturize libpasteurize past queue reprlib socketserver tkinter winreg xmlrpc)
  ln -s ~/src/python-future/src/$d
end

[snarfed]

getting close! the python3 branches of granary, bridgy, oauth-dropins, and webutil are all fully migrated to 2/3 compatible and all unit tests pass.

[snarfed]

woo, done! and merged into master. will be released in v1.12.