python判断当月有多少天

def get_last_day(year, month):
    # 判断是否为闰年，当flag为True时，表示是闰年
    flag = False
    if year%4 == 0 and year%100 != 0:
        flag = True
    if year%400 == 0:
        flag = True
    if month in [1,3,5,7,8,10,12]:
        return 31
    if month in [4,6,9,11]:
        return 30
    if month == 2 and flag == True:
        return 29
    if month == 2 and flag == False:
        return 28

以后说不定用得上