aocd6.py

orbits = {y:x for x,y in [x.split(')') for x in ip.split("\n")]}

def indirect_orbits(obj, orbits):
    if obj not in orbits:
        return []
    
    return [orbits[obj]] + indirect_orbits(orbits[obj], orbits)


def orbital_swaps_setbased(start, end, orbits):
    steps = 0
    left = set(indirect_orbits(start, orbits))
    right = set(indirect_orbits(end, orbits))
    
    return len(left ^ right)