HTSeq for high through put sequencing data
http://www-huber.embl.de/users/anders/HTSeq/doc/overview.html
Cogent
https://pypi.python.org/pypi/cogent
pygr
http://code.google.com/p/pygr/
pybedtools
http://pythonhosted.org/pybedtools/
TAMO for motif analysis
http://fraenkel.mit.edu/TAMO/TAMO_tutorial.html