Concatenate 2D numpy array with an empty array

Question

This Python 3.8 code snippet:

a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6]])
a = np.concatenate((a, b), axis=0)
print(a) 

produces:

[[1 2]
 [3 4]
 [5 6]]

as expected. How do I define an empty array e , such that this code produces the same result:

# define en empty array e here
a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6]])
e = np.concatenate((e, a), axis=0)
e = np.concatenate((e, b), axis=0)
print(e) 

Answer 1

Found it:

e = np.empty((0, 2))
a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6]])
e = np.concatenate((e, a), axis=0)
e = np.concatenate((e, b), axis=0)
print(e)