Cyber Challenge Infection

import sys

def is_valid(i, j, N, M):
    return i >= 0 and i < N and j >= 0 and j < M

def get_neighbors(i, j, N, M):
    neighbors = [
        (i - 1, j),
        (i + 1, j),
        (i, j + 1),
        (i, j - 1),
        (i + 1, j + 1),
        (i - 1, j - 1),
        (i + 1, j - 1),
        (i - 1, j + 1),
    ]

    return [x if is_valid(x[0], x[1], N, M) else None for x in neighbors]

def get_categories_amount(neighbors, field):
    malware = 0 # *
    data = 0 # +

    for neighbour in neighbors:
        if(neighbour is not None):
            if(field[neighbour[0]][neighbour[1]] == '*'):
                malware += 1

            if(field[neighbour[0]][neighbour[1]] == '+'):
                data += 1

    return [malware, data]

def make_choice(neighbors_categories, my_self):
    [malwares, data] = neighbors_categories

    if(my_self == '.'):
        if((data + malwares) > 4):
            return '+'

    if(my_self == '+'):
        if((data + malwares) > 4):
            return '*'
        if((data + malwares) < 4):
            return '.'

    if(my_self == '*'):
        if((data + malwares) > 4):
            return '+'
        if((data + malwares) < 4):
            return '.'

    return my_self

def print_field(field):
    for r in field:
        print("".join(r))

def clone_field(field, N, M):
    next_field = [(['#'] * M) for _ in range(N)]
    for i in range(N):
        for j in range(M):
            next_field[i][j] = field[i][j]

    return next_field

def solve(fin):
    (N, M, K) = map(int, fin.readline().strip().split())
    g = []
    for _ in range(N):
        g.append(list(fin.readline().strip()))

    next_field = [(['#'] * M) for _ in range(N)]
    for _ in range(K):
        for i in range(N):
            for j in range(M):
                neighbors = get_neighbors(i, j, N, M)
                neighbors_categories = get_categories_amount(neighbors, g)
                next_field[i][j] = make_choice(neighbors_categories, g[i][j])
        g = clone_field(next_field, N, M)

    print_field(next_field)

if __name__ == "__main__":
    solve(sys.stdin)