Python - 从年和工作日获取月份

给定年份和工作日，任务是编写一个Python程序来获取月份和星期。

例子：

Input : test_year = 1997, test_week = 27
Output : 1997-07-07 00:00:00
Explanation : 27th Week starts from 7 july in 1997.

Input : test_year = 2021, test_week = 27
Output : 2021-07-05 00:00:00
Explanation : 27th Week starts from 5 july in 2021.

方法 #1：使用 %W, %w

用 %W 解析日期将我们设置为开始一周，另外， %w 获取所需的工作日，我们将使用默认值为 1。可以根据需要进行调整。

Python3

# Python3 code to demonstrate working of
# Start week from year and weekday
# Using %W, %w
from datetime import datetime, timedelta
  
# initializing year
test_year = 1997
  
# initializing week
test_week = 27
               
# printing original date
print("The original year, week is : " + str(test_year) + " " + str(test_week))
  
date = str(test_year) + '-W' + str(test_week)
  
# getting date
res = datetime.strptime(date + '-1', "%Y-W%W-%w")
  
# printing result
print("The starting date of week : " + str(res))

输出：

The original year, week is : 1997 27
The starting date of week : 1997-07-07 00:00:00

方法#2：使用relativedelta()

这只是将所需的周数添加到所需的年份并获得所需的初始日期。这增加了几周，因此可以根据一年的开始日期给出任何工作日。

蟒蛇3

# Python3 code to demonstrate working of
# Start week from year and weekday
# Using relativedelta()
import datetime
from dateutil.relativedelta import relativedelta
  
# initializing year
test_year = 1997
  
# initializing week
test_week = 27
               
# printing original date
print("The original year, week is : " + str(test_year) + " " + str(test_week))
  
# contructing date
date = datetime.date(test_year, 1, 1)
  
# getting date by adding weeks to year beg. 
# prints 9 July. as 1 jan was wednesday, 27th 
# weeks beginning is from wed.
res = date + relativedelta(weeks = +test_week)
  
# printing result
print("The starting date of week : " + str(res))

输出：

The original year, week is : 1997 27
The starting date of week : 1997-07-09