lala.py

import time
numbers = [9] * 20
carry = 0


def foo(num):
    global carry
    sum = num + 1 + carry
    if sum < 10:
        return  sum
    else:
        carry = 1
        return 0

now = time.time()
new_numbers = list(map(foo, numbers[::-1]))[::-1]
new_numbers.insert(0, carry) if carry else new_numbers
then = time.time()

print(new_numbers, then - now)

carry = 0
new_numbers = []
now = time.time()
for number in numbers[::-1]:
    sum = number + 1 + carry
    if sum < 10:
        new_numbers = [sum, *new_numbers]
    else:
        carry = 1
        new_numbers = [0, *new_numbers]
new_numbers.insert(0, carry) if carry else new_numbers
then = time.time()

print(new_numbers, then - now)