I had quick a look inisde the Ubuntu 12.04 package for python-magic and it definitely appears to be the same library as on pip, it's just a very old version which doesn't appear to be very useful at all, also it's not versioned correctly, it has the same version as libmagic (5.09-2) but it should really by 0.4.6 if the latest from pip was to be packaged.
I had quick a look inisde the Ubuntu 12.04 package for python-magic and it definitely appears to be the same library as on pip, it's just a very old version which doesn't appear to be very useful at all, also it's not versioned correctly, it has the same version as libmagic (5.09-2) but it should really by 0.4.6 if the latest from pip was to be packaged.