在python中查找上一周/上周的星期五

Question

Eg1。假设我有一天是2007年4月30日。那么我需要到2007年4日27日。

Eg2.假设我有一天是2007年6月29日。那么我需要到2007年6日22日。

Answer 1

假设day是datetime.date或datetime.datetime对象，则此代码为上周的星期五创建一个datetime/date对象：

friday = day - timedelta(days=day.weekday()) + timedelta(days=4, weeks=-1)

说明：timedelta(days=day.weekday())是星期一和day之间的偏移量，所以加4天减去一周就会得到上周的星期五。

当然你可以简化这个（+4d -1w = -3d）：

friday = day - timedelta(days=day.weekday() + 3)

注意：要获得timedelta，请使用from datetime import timedelta或仅使用import datetime，然后使用datetime.timedelta

Answer 2

另一种更简单的方法是使用python-dateutil。获取上周五：

>>> from dateutil.relativedelta import relativedelta, FR
>>> from datetime import datetime
>>> datetime(2015, 7, 8) + relativedelta(weekday=FR(-1))
datetime.datetime(2015, 7, 3, 0, 0)

下周五：

>>> datetime(2015, 7, 8) + relativedelta(weekday=FR(+1))
datetime.datetime(2015, 7, 10, 0, 0)

Answer 3

不是特定于周五，而是给定一天"taget_dayofweek"（其中周一为0，周日为6）

from datetime import datetime
target_dayofweek = 4  # Friday
current_dayofweek = datetime.now().weekday() # Today

if target_dayofweek <= current_dayofweek:
    # target is in the current week
    endDate = datetime.now() - timedelta(current_dayofweek - target_dayofweek)
else: 
    # target is in the previous week
    endDate = datetime.now() - timedelta(weeks=1) + timedelta(target_dayofweek - current_dayofweek)

Answer 4

pandas.tseries.offset中有很多选项这是上星期五的。

from pandas.tseries.offsets import Week
f_dates = required_df.index - Week(1, weekday=4)

Answer 5

date_object = datetime.date.today()
from dateutil.relativedelta import relativedelta
previousWeekLastDay = date_object + relativedelta(weekday=SU(-1))
previousWeekFirstDay = previousWeekLastDay + relativedelta(weekday=MO(-1))
print(previousWeekFirstDay)
print(previousWeekLastDay)
previoustopreviousWeekLastDay1= date_object + relativedelta(weekday=SU(-2))
previoustopreviousWeekFirstDay1= previousWeekLastDay1 + relativedelta(weekday=MO(-1))
print(previoustopreviousWeekFirstDay1)
print(previoustopreviousWeekLastDay1)