>>> L = [1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1]
>>> import itertools
>>> import operator
>>> [[i for i,value in it] for key,it in itertools.groupby(enumerate(L), key=operator.itemgetter(1)) if key != 0]
[[0, 1, 2, 3], [9, 10, 11], [14, 15], [20, 21]]