advent_of_code/2021/2/2_2.py

#!/usr/bin/env python
# 2021 - Advent Of Code - 2 part 2

import re

x = 0
y = 0
aim = 0

re_parse = re.compile(r'(forward|up|down) (\d+)')

with open('input.txt', encoding="utf-8") as f:
    for line in f:
        m = re_parse.match(line)
        direction, unit = m.group(1), int(m.group(2))
        if direction == 'up':
            aim -= unit
        elif direction == 'down':
            aim += unit
        elif direction == 'forward':
            x += unit
            y += aim * unit

print(f'position: ({x}, {y}) => {x*y}')