A viable solution for Python concurrency

It may seriously be easier for a python4 and just changing the API for C extensions ....this pains me (especially as I hate how 2.7 was handled) but we're used to 2.7 and 3.x being around.... why not just go for 4?

It can't be more painful surely?

BTW I get a choice (and it's one that must be made) between:
Python 3.4.3
and
Python 2.7.6

I am aware these are both ancient, this means I can't use half the new stuff anyway, so maybe that'd cause pain?

But yeah I'm used to python/python3 - why not python4....

It really couldn't be worse and this is worth getting right