python – TypeError: numpy.float64 object is not callable

Python does not follow the same rules as written math. You must explicitly indicate multiplication.

(a)(b)

(unless a is a function)

(a) * (b)

This error also occurs when your function has the same name as your return value

def samename(a, b):
    samename = a*b
    return samename

This might be a super rookie mistake, I am curious how often this answer will be helpful.

You are missing * when multiplying, try:

import numpy as np
yy = np.arange(4)
xx = np.arange(5)
Area = ((xx[2] - xx[1])*(yy[2] + yy[1])) / 2

,