Sum prime non prime 3\12

prime_num_sum = 0
non_prime_num_sum = 0
command = input()

while command != 'stop':
    current_num = int(command)

    if current_num < 0:
        print('Number is negative.')
        command = input()
        continue

    num_is_prime = True
    for num in range(2, current_num):
        if current_num % num == 0:
            num_is_prime = False
            break

    if num_is_prime:
        prime_num_sum += current_num
    else:
        non_prime_num_sum += current_num
    command = input()

print(f'Sum of all prime numbers is: {prime_num_sum}')
print(f'Sum of all non prime numbers is: {non_prime_num_sum}')