They are in:

/usr/lib/python2.7
/usr/lib/python3.3
/usr/lib/python3.4

To see where a library is:

_$: python -v
>>> import logging
import logging # directory /usr/lib/python2.7/logging
# /usr/lib/python2.7/logging/__init__.pyc matches /usr/lib/python2.7/logging/__init__.py
import logging # precompiled from /usr/lib/python2.7/logging/__init__.pyc
...
>>>