numpy.count_nonzero(a)
Counts the number of non-zero values in the array a. Parameters:
a : array_like The array for which to count non-zeros. Returns:
count : int or array of int Number of non-zero values in the array. See also
nonzero
Return the coordinates of all the non-zero values. Examples >>> np.count_nonzero(np.eye(4))
4
>>> np.count_nonzero([[0,1,7,0,0],[3,0,0,2,19]])
5