python--calculates the date of 5 last week

The first method:

From datetime import datetime, Timedelta  weekdays = [' Monday ', ' Tuesday ', ' Wednesday ', ' Thursday ',              ' Friday ', ' Saturday ', ' Sunday ']  def get_previous_byday (Dayname, Start_date=none):      if start_date is None:          start_date = Datetime.today ()      day_num = Start_date.weekday ()      day_num_target = Weekdays.index (dayname)      Days_ago = (7 + Day_num-day_num_target)% 7      if Days_ago = = 0:          days_ago = 7      target_date = Start_date-timedelta (days = Day S_ago)      return target_date print (    datetime.today ())  print (Get_previous_byday (' Monday '))  print (Get_previous_byday (' Monday ', DateTime (2016, 8, 28)))

The second method, with the Dateutil module

From datetime import datetime from  dateutil.relativedelta import Relativedelta from  dateutil.rrule import *  d = DateTime.Now () print (d) Print (d  + Relativedelta (weekday=fr))  print (d + relativedelta (weekday=fr (-1)))

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