numpy.flatnonzero(a)
Return indices that are non-zero in the flattened version of a.
This is equivalent to np.nonzero(np.ravel(a))[0].
Parameters:aarray_likeInput data.
Returns:resndarrayOutput array, containing the indices of the elements of a.ravel() that are non-zero.
See also
Return the indices of the non-zero elements of the input array.
Return a 1-D array containing the elements of the input array.
Examples
>>> importnumpyasnp>>> x=np.arange(-2,3)>>> xarray([-2, -1, 0, 1, 2])>>> np.flatnonzero(x)array([0, 1, 3, 4])Use the indices of the non-zero elements as an index array to extract these elements:
>>> x.ravel()[np.flatnonzero(x)]array([-2, -1, 1, 2])