日期

import datetime 

date01 = "2021-05-01"
date02 = "2024-01-01"

y, m, d = list(map(int, date01.split('-')))
dt = datetime.datetime(year = y, month = m, day = d)

y, m, d = list(map(int, date02.split('-')))
dt2 = datetime.datetime(year = y, month = m, day = d)

# 输出日期的年月日
print("%d-%d-%d" % (dt.year, dt.month, dt.day))

# 计算新的日期，向前向后
dt = dt + datetime.timedelta(days = 31)
dt = dt + datetime.timedelta(days = -31)
# 两个日期的减法
delta = dt - dt2 # datetime.timedelta类型
print(delta.days)