Fix Python – Numpy – add row to array

How does one add rows to a numpy array?
I have an array A:
A = array([[0, 1, 2], [0, 2, 0]])

I wish to add rows to this array from another array X if the first element of each row in X meets a specific condition.
Numpy arrays do not have a method ‘append’ like that of lists, or so it seems.
If A and X were lists I would merely do:
for i in X: