791. Custom Sort String

Sort a string according to the given order: Anything that doesn’t have an order can be placed at the beginning or the end, so I placed it at the end.

class Solution:
    def customSortString(self, order: str, s: str) -> str:
        ordering = {c: i + 1 for i, c in enumerate(order)}
        return ''.join(sorted(s, key=lambda x: ordering.get(x, 0)))