Day 1

In: %timeit sum([calculate_fuel(int(mass)) for mass in lines])              34.9 µs ± 235 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)In: %timeit calculate_fuel(data).sum()                                      5.29 µs ± 84.6 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)