center.py

import numpy as np

HORIZONTAL = 1
VERTICAL = 0

def first_nonzero(arr, axis, invalid_val=-1):
    mask = arr!=0
    return np.where(mask.any(axis=axis), mask.argmax(axis=axis), invalid_val)

def last_nonzero(arr, axis, invalid_val=-1):
    mask = arr!=0
    val = arr.shape[axis] - np.flip(mask, axis=axis).argmax(axis=axis) - 1
    return np.where(mask.any(axis=axis), val, invalid_val)

arr = np.array(
        [
        [0, 0, 0, 0, 0],
        [0, 0, 0, 0, 0],
        [0, 0, 1, 1, 0],
        [0, 0, 1, 1, 0],
        [0, 0, 0, 0, 0]
        ])

first_hor = first_nonzero(arr, axis=HORIZONTAL, invalid_val=np.nan)
first_vert = first_nonzero(arr, axis=VERTICAL, invalid_val=np.nan)

top = np.nanmin(first_vert)
left = np.nanmin(first_hor)


last_hor = last_nonzero(arr, axis=HORIZONTAL, invalid_val=np.nan)
last_vert = last_nonzero(arr, axis=VERTICAL, invalid_val=np.nan)

bottom = np.nanmax(last_vert)
right = np.nanmax(last_hor)


print("top, left, bottom, right")
print(top, left, bottom, right)

x = (right + left) / 2
y = (bottom + top) / 2

print(x, y)