How do I get a list of indices of non zero elements in a list?
Not really a "new" answer but numpy has this built in as well.
import numpy as np
a = [0, 1, 0, 1, 0, 0, 0, 0]
nonzeroind = np.nonzero(a)[0] # the return is a little funny so I use the [0]
print nonzeroind
[1 3]
Since THC4k mentioned compress (available in python2.7+)
>>> from itertools import compress, count
>>> x = [0, 1, 0, 1, 0, 0, 0, 0]
>>> compress(count(), x)
<itertools.compress object at 0x8c3666c>
>>> list(_)
[1, 3]
[i for i, e in enumerate(a) if e != 0]