python3 customized compare function

https://stackoverflow.com/questions/2531952/how-to-use-a-custom-comparison-function-in-python-3

How to use a custom comparison function in Python 3?

https://stackoverflow.com/questions/5213033/sort-a-list-of-lists-with-a-custom-compare-function

Sort a list of lists with a custom compare function

 

import sys
from functools import cmp_to_key
 
def compare(a, b): # a가 왼쪽 원소, b가 오른쪽 원소
    if b[1] != a[1]: return b[1] - a[1] # 이게 양수면 a, b 바꿈
    else:
        if b[0] == a[0]: return 0 # 0 이면 a, b간 선후관계 없음
        else: return b[0] - a[0]
 
n = int(input())
v = [list(map(int, sys.stdin.readline().split())) for _ in range(n)]
v.sort(key=cmp_to_key(compare))
print(v)cs