python - 使用python获取当月的最后一个星期四

Question

关注此answer我试图获取当月最后一个星期四的日期。但是我的代码没有跳出循环。

from datetime import datetime
from dateutil.relativedelta import relativedelta, TH

todayte = datetime.today()
cmon = todayte.month

nthu = todayte
while nthu.month == cmon:
    nthu += relativedelta(weekday=TH(1))
    #print nthu.strftime('%d%b%Y').upper()

Answer 1

查看 relativedelta 的文档

Notice that if the calculated date is already Monday, for example, using (0, 1) or (0, -1) won’t change the day.

如果 nthu 已经是星期四，那么添加 TH(1) 或 TH(-1) 不会有任何效果，但会导致同一日期，这就是您的循环无限运行的原因。

我假设一个月最多 5 周，并按以下方式进行:

todayte = datetime.today()
cmon = todayte.month

for i in range(1, 6):
    t = todayte + relativedelta(weekday=TH(i))
    if t.month != cmon:
        # since t is exceeded we need last one  which we can get by subtracting -2 since it is already a Thursday.
        t = t + relativedelta(weekday=TH(-2))
        break