No discussion of python packaging without mention of conda is complete. It's as good as "apt-get" for Python (and not just for Python, but ... mostly for Python).
I believed that! Then I actually used it and got incompatible packages, packages only for 32 bit XOR 64 bit etc. It was not remotely as good as the package managers I am used to on several distros. :(
http://conda.pydata.org/miniconda.html