备战蓝桥杯python——datetime日期类函数

datetime函数

• datetime.date()
  设置指定日期

>>> import datetime
>>> date = datetime.date(2002, 9, 13)
>>> print(date)
2002-09-13

• datetime.date.today()
  获取今天的日期信息

>>> print(datetime.date.today())
2023-03-09

• datetime.date.weekday()
  返回当天是周几，0为周一，1为周二

>>> date.weekday()
4

• isocalendar(...)
  返回指定日期的年，第几周，周几

>>> t.isocalendar()
datetime.IsoCalendarDate(year=2023, week=10, weekday=4)

• isoformat(...)
  按格式返回’YYYY-MM-DD

>>> t.isoformat()
'2023-03-09'

• timedelta(...)
  进行日期的加减操作

>>> delta = datetime.timedelta(days=-1)
>>> print(t+delta)
2023-03-09

例题：星期计算

import datetime

t1  = datetime.date(2000, 1, 1)
t2 = datetime.date(2020, 10, 1)
delta = datetime.timedelta(days=1)
res = 0
while (t1<=t2):
    if(t1.strftime("%d")=="01" or t1.weekday()==0):
        res+=2
    else:
        res+=1
    t1+=delta

print(res)