Number of unique elements per row in a NumPy array

Question

For example, for

a = np.array([[1, 0, 0], [1, 0, 0], [2, 3, 4]])

I want to get

[2, 2, 3]

Is there a way

Answer 1

A oneliner using sort:

In [6]: np.count_nonzero(np.diff(np.sort(a)), axis=1)+1
Out[6]: array([2, 2, 3])