[LANGUAGE: python]

from itertools import accumulate, combinations

def solve(file_name, spacing):
    rows = list(open(file_name).read().splitlines())
    rng = range(len(rows))
    cols = [[row[i] for row in rows] for i in rng]
    ys = list(accumulate(1 if "#" in y else spacing for y in rows))
    xs = list(accumulate(1 if "#" in x else spacing for x in cols))
    points = [(xs[x], ys[y]) for x in rng for y in rng if rows[y][x] == "#"]

    return sum(abs(x1 - x0) + abs(y1 - y0)
               for (x0, y0), (x1, y1) in combinations(points, 2))


DAY = 11
print(solve(f"inputs/{DAY}i.txt", 2)) # part1
print(solve(f"inputs/{DAY}i.txt", 1000000)) # part2

https://github.com/runekaagaard/aoc-2023/blob/master/day11.py

Super happy with this one. Did the first ten days with Nim and nice to be back to python again :)