Index Python List with Numpy Boolean Array
map(x.__getitem__,np.where(mask)[0]) 
Or if you want list comprehension
[x[i] for i in np.where(mask)[0]]
This keeps you from having to iterate over the whole list, especially if mask is sparse.
Is there a way to index a python list like x = ['a','b','c'] using a numpy boolean array? I'm currently getting the following error: TypeError: only integer arrays with one element can be converted to an index