This is called the “shape” in NumPy, and can be requested via the .shape attribute:
>>> a = zeros((2, 5))
>>> a.shape
(2, 5)
If you prefer a function, you could also use numpy.shape(a).
Yes numpy has a size function, and shape and size are not quite the same.
Input
import numpy as np
data = [[1, 2, 3, 4], [5, 6, 7, 8]]
arrData = np.array(data)
print(data)
print(arrData.size)
print(arrData.shape)
Output
[[1, 2, 3, 4], [5, 6, 7, 8]]
8 # size
(2, 4) # shape