Find the largest Island - Problem

import numpy as np
import pandas as pd

np.random.seed(42)

MAX_LEN = 5

def recursive_update(x, y):
    """Recursively updates the neightbouring element to 0 and resturn collected count by udating."""
    global data
    if x  MAX_LEN and y  MAX_LEN:
        # invalid location
        return 0
    count = 0
    if data[x, y] == 1:
        data[x, y] = 0
        count = 1
        if x + 1  0:
            count += recursive_update(x - 1, y)
        if y > 0:
            count += recursive_update(x, y - 1)
        if y + 1  .5)

print(data)

for row in range(len(data)):
    for col in range(len(data[0])):
        score = recursive_update(row, col) 
        if score:
            print((score, data))