For this sweetness of course no python PEP is needed, but here comes the beauty:

~/.local is kind of a new standard directory which is a “standard” suggested by freedesktop.org and already used by some other applications and

python ./setup.py install –user

will automatically install the required package there – which again is no big thing and could be archived via PREFIX=~/.local/ but this is feels natural, pythonic, good. All now left to do is to add ~/.local/bin to the PATH-variable and ~/.local/lib/python<version>/site-packages/ to the PYTHONPATH (you should imo do this in ~/.profile).

So, using this, your virtualenv-usage might significantly decrease (though it does not make virtual environments useless).