Python程序获取给定日期后的第n个工作日

给定一个日期和工作日索引，任务是编写一个Python程序来获取给定日期之后的给定星期几的日期。工作日指数基于下表：

Index	Weekday
0	Monday
1	Tuesday
2	Wednesday
3	Thursday
4	Friday
5	Saturday
6	Sunday

例子：

Input : test_date = datetime.datetime(2017, 3, 14), weekday_idx = 4

Output : 2017-03-17

Explanation : 14 March is Tuesday, i.e 1 weekday, 4th weekday is a Friday, i.e 17 March.

Input : test_date = datetime.datetime(2017, 3, 12), weekday_idx = 5

Output : 2017-03-18

Explanation : 12 March is Sunday, i.e 6th weekday, 5th weekday in next week is a Sturday, i.e 18 March.

编程需要懂一点英语

方法 #1：使用timedelta() + weekday()

在这种情况下，我们从工作日索引中减去日期工作日，然后检查提取的所需索引，然后检查所需的日期，如果负数与 7 相加，然后使用 timedelta() 将所得数字添加到当前日期。

Python3

# Python3 code to demonstrate working of
# Next weekday from Date
# Using timedelta() + weekday()
import datetime
  
# initializing dates
test_date = datetime.datetime(2017, 3, 14)
  
# printing original date
print("The original date is : " + str(test_date)[:10])
  
# initializing weekday index
weekday_idx = 4
  
# computing delta days
days_delta = weekday_idx - test_date.weekday()
if days_delta <= 0:
    days_delta += 7
  
# adding days to required result
res = test_date + datetime.timedelta(days_delta)
  
# printing result
print("Next date of required weekday : " + str(res)[:10])

Python3

# Python3 code to demonstrate working of
# Next weekday from Date
# Using lamnda function
import datetime
  
# initializing dates
test_date = datetime.datetime(2017, 3, 14)
  
# printing original date
print("The original date is : " + str(test_date)[:10])
  
# initializing weekday index
weekday_idx = 4
  
# lambda function provides one liner shorthand
def lfnc(test_date, weekday_idx): return test_date + \
    datetime.timedelta(days=(weekday_idx - test_date.weekday() + 7) % 7)
  
  
res = lfnc(test_date, weekday_idx)
  
# printing result
print("Next date of required weekday : " + str(res)[:10])

输出：

The original date is : 2017-03-14
Next date of required weekday : 2017-03-17

方法 #2：使用lambda函数

使用 lambda函数为该问题提供了一种简明而紧凑的解决方案。

蟒蛇3

# Python3 code to demonstrate working of
# Next weekday from Date
# Using lamnda function
import datetime
  
# initializing dates
test_date = datetime.datetime(2017, 3, 14)
  
# printing original date
print("The original date is : " + str(test_date)[:10])
  
# initializing weekday index
weekday_idx = 4
  
# lambda function provides one liner shorthand
def lfnc(test_date, weekday_idx): return test_date + \
    datetime.timedelta(days=(weekday_idx - test_date.weekday() + 7) % 7)
  
  
res = lfnc(test_date, weekday_idx)
  
# printing result
print("Next date of required weekday : " + str(res)[:10])

输出：

The original date is : 2017-03-14
Next date of required weekday : 2017-03-17