Aiohttp: Discussion: drop Python 3.5 support

[asvetlov]

Now aiohttp is Python 3.5 compatible.

The latest Debian Buster (released about 2 weeks ago) has Python 3.7 by default.
RHEL 8 (released on May 7th, 2019) has Python 3.6 by default.

I believe there is no sense in Python 3.5 support for aiohttp 4.0

In #3928 @AMDmi3 expressed an opinion that he is not interested in a contribution for legacy Python version.
In #3946 @ayushkovskiy used Python 3.6 syntax.
IIRC @samuelcolvin asked for dropping 3.5 a half year ago.

Python 3.5 is in security-fixing mode and going to EOL soon.

Do somebody object for Python 3.5 support dropping?
Opinions?

[kxepal]

+1 to drop 3.5. Quite soon there will be 3.8, so having 4 Python releases on the support board will be quite expensive (and demotivating).

[webknjaz]

Let's drop it w/ aiohttp==4.0. Fedora also has Python 3.7 almost since the day of its release. Ubuntu/Debian will always be PITA. Let the users figure out their problems on their own.

[yjqiang]

So the next release would be aiohttp==4.0?

[webknjaz]

@yjqiang next major release. We'll probably still backport some bugfixes to 3.5, just not features.

[asvetlov]

Hmm, there is a blocker called PyPy.
PyPy3 3.6 is in beta phase still. aiohttp supports PyPy now, so we cannot drop 3.5 until PyPy3 3.6 will be released :(

[webknjaz]

I don't think it's a big deal. PyPy users can keep using aiohttp<=3.5 until it's ready.

[asvetlov]

Do you propose dropping PyPy from travis build matrix for now?

[webknjaz]

It should work under pypy3 3.6 beta, which is actually available on Travis