Tsort is a topological sort for python. Its interface is based on the tsort shell command.
""" tsort is a python implementation of the tsort(1) shell command
partials is a list of lists of partial orders.
tsort([['a','b','c'],['d'],['e', 'f'], ['b','c','d','e']])
should return ['a', 'b', 'c', 'd', 'e', 'f']
Copyright Nathan Hurst 2001
Licenced under the GNU LGPL. see COPYING for details.
"""