Migration to Python3 about clay HOT 8 CLOSED

@kroko moving to py3 is a question of "when" only, since pyethereum will drop py2 support this year. Dependencies that does not support py3 will be dropped one by one. E.g. see branch gevent-pydevp2p.

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Please, kill Python 2
Python 3 should be much much easier when you write async code

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Do we want do switch to Python 3 or support both 2 and 3?

It seems to be quite difficult to support both, mostly because of dependencies. E.g. Python2 has a external package ipaddr (by Google), Python3 has a built in package ipaddress (based on ipaddr) and ipaddr is syntax-incompatible with Python3.

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In my opinion it makes no sense to support both. We will probably add whole python directory to a final app anyway, so it should be just Python 3.

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There are many problems with combination of Twisted, Python3 and Windows.

Twisted is claiming: "Ideally we could omit a number of them: twisted.python.win32 - windows is not a target platform for the initial release."

Source: https://twistedmatrix.com/trac/wiki/Plan/Python3].

Some functions are badly tested, there are fixes for some of them but not necessarily active in official releases. We can try to patch twisted by hand: (change file to open, change implements to @Implementer), but it will not be tested and may lead to unexpected behaviours on windows.

There is much better library for Python3 called asyncio, but moving to this new platform may be time-absorbing.

I propose to stay with Python2 during development of Python render but we may return to this topic in the future.

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At least pyethereum has been ported to Python 3 recently.

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We would do that if it was up to us only, but we have dependencies that does not support Py3.

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which deps are holding you back to deploy on py3 (which. is. the. future.) and have no alternatives?

i do network renderings in cycles (inhouse modded blender netrender, i will not push it upstream as long as they stay on svn not git, who has time for that? :) ) as well as have contributed to lux in the context of amd gpus & building @ macOS. i am very optimistic about what golem could bring. you do know that even blender that is your proof of concept example uses:

>>> import sys
>>> print(sys.version_info)
#sys.version_info(major=3, minor=5, micro=1, releaselevel='final', serial=0)

right?

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