I believe the general formula is apt-get for python and python-pip, then use pip for everything past that point.
And in general, virtualenvs are the right way to go for anything other than throwaway scripts. I've got a global numpy/scipy/requests install so that I can just do `ipython -pylab` and start getting work done. But real project code happens in a virtualenv.
On a mac anaconda works pretty well. I sent a link to a marketer with minimal python experience and she was up and running in under an hour. (Admittedly, she's rather more adept than a normal marketer...)
First of all, you can use APT to install older versions. Second, you can always make up a case where the packages in the repos don't do 100% what you desire (maybe you want some different build options, or dependency versions, etc). The packages in the repos are designed to cover most cases, and to work together with the other packages on your system. So I have to ask: are you SURE you need something the packages don't give you? If so, then you have agreed to take on the extra work to get what you want, and it's understood that it may/may not be trivial. This applies to any software.
Even so, APT does help you quite a bit with build dependencies, so whatever non-standard thing you've decided to do, you can still do it with (hopefully) not too much work. Feel free to ask me about any specific thing you're having trouble with.
Why is installing a specific version of a package you fancy (e.g the latest or some previous) a nightmare?
And there "apt-get" doesn't help you much.