serious conflicts between python pks installed via yum vs pip

[Neal Becker]

I've seen this repeatedly, with often very serious consequences (complete 
failure of update from f15->f16 for example).

Between packages installed via pip, and packages installed via yum, some 
packages seem to switch between

e.g.,
numpy-1.6.1-py2.7.egg-info

being installed as a file and the same name being installed as a directory.  
This can cause subsequent rpm update (via cpio) to abort.

I don't know what's causing this, but IMO this is a serious problem.