上周五如何获得？

Question

下面的代码应在上周五的16:00:00返回。但它返回上周的星期五。如何解决？

now = datetime.datetime.now()
test = (now - datetime.timedelta(days=now.weekday()) + timedelta(days=4, weeks=-1))
test = test.replace(hour=16,minute=0,second=0,microsecond=0)

更新。我现在使用以下方法-最好的方法吗？

now = datetime.datetime.now()
if datetime.datetime.now().weekday() > 4:
    test = (now - datetime.timedelta(days=now.weekday()) + timedelta(days=4))
else:
    test = (now - datetime.timedelta(days=now.weekday()) + timedelta(days=4, weeks=-1))
test = test.replace(hour=16,minute=0,second=0,microsecond=0)

Upd2。仅举一个例子。假设今天是 2012年10月5日 。如果当前时间等于或小于 16:00 ，则应返回 2012年9月28日 ，否则返回
2012 年 10月5日 。

Answer 1

与链接的问题一样，您需要使用datetime.date对象而不是datetime.datetime。要获得datetime.datetime最终结果，可以使用datetime.datetime.combine()：

import datetime

current_time = datetime.datetime.now()

# get friday, one week ago, at 16 o'clock
last_friday = (current_time.date()
    - datetime.timedelta(days=current_time.weekday())
    + datetime.timedelta(days=4, weeks=-1))
last_friday_at_16 = datetime.datetime.combine(last_friday, datetime.time(16))

# if today is also friday, and after 16 o'clock, change to the current date
one_week = datetime.timedelta(weeks=1)
if current_time - last_friday_at_16 >= one_week:
    last_friday_at_16 += one_week