Drop Python 2.4 and 2.5 support

[giampaolo]

Main reason: I'm tired of providing the 2 extra exe installers for Windows requiring mingw32. Furthermore I can get rid of a lot of cruft in _compat.py (namedtuple, property, defaultdict, functools.wraps) and I can finally freely use the with statement, "except Exception as:", u"" and b"" syntax.
Also, current 2.1.1 version is very stable therefore those few users who are still on Python 2.4/2.5 can simply install 2.1.1.

[giampaolo]

Patch here: https://gist.github.com/giampaolo/b0981122e2c4cd8d19f0

[tshepang]

👍

[ddaeschler]

Just a note that #536 concerns RHEL/CENTOS 5. I just installed a VM for this version of linux and by default it had python 2.4 installed:

[root@localhost psutil]# python -V
Python 2.4.3

[giampaolo]

Thanks for your input David. Do you have an opinion about this?
According to this https://access.redhat.com/articles/3078 RH5 was released in 2007.
I don't know how much of those distros are still in use nowadays, but I have a feeling they are not rare. :-\

[ddaeschler]

I think there are likely a lot of CentOS5/RHEL5 machines still humming along in production environments, however since RHEL7 and CentOS7 have now been released, they are 2 major versions behind.

I think it would be good enough to let people know they'd need to use an older psutil release on those systems and if they need newer functionality that they would have to update their systems.

For the future, CentOS6 and RHEL6 package Python 2.6 in their installs, and I'd say the same would go for them in a few years if you deprecate Python 2.6, even though those are the versions I run in production.

[ddaeschler]

Note also that RHEL stops delivering software enhancements after 5.5 years according to their lifecycle document: https://access.redhat.com/support/policy/updates/errata .