Python程序来查找月份的最后日期

给定一个 datetime 对象，任务是编写一个Python程序来计算 datetime 对象 Month 的最后一个日期。

例子：

Input : test_date = datetime.datetime(2018, 6, 4)

Output : 30

Explanation : April has 30 days, each year

Input : test_date = datetime.datetime(2020, 2, 4)

Output : 29

Explanation : February had 29 days in 2020, leap year.

方法#1：使用replace() + timedelta()

在此，提取下个月，减去从下个月提取的下个月对象的日期，得到下个月开始前1天，即当月的最后日期。

Python3

# Python3 code to demonstrate working of
# Get Last date of Month
# Using replace() + timedelta()
import datetime
 
# initializing date
test_date = datetime.datetime(2018, 6, 4)
              
# printing original date
print("The original date is : " + str(test_date))
 
# getting next month
# using replace to get to last day + offset
# to reach next month
nxt_mnth = test_date.replace(day=28) + datetime.timedelta(days=4)
 
# subtracting the days from next month date to
# get last date of current Month
res = nxt_mnth - datetime.timedelta(days=nxt_mnth.day)
 
# printing result
print("Last date of month : " + str(res.day))

输出：

The original date is : 2018-06-04 00:00:00
Last date of month : 30

方法#2：使用 calendar()

这使用内置函数来解决这个问题。在此，给定年份和月份，可以使用 monthrange() 计算范围，其第二个元素可以获得所需的结果。

蟒蛇3

# Python3 code to demonstrate working of
# Get Last date of Month
# Using calendar()
from datetime import datetime
import calendar
 
# initializing date
test_date = datetime(2018, 6, 4)
              
# printing original date
print("The original date is : " + str(test_date))
 
# monthrange() gets the date range
# required of month
res = calendar.monthrange(test_date.year, test_date.month)[1]
 
# printing result
print("Last date of month : " + str(res))

输出：

The original date is : 2018-06-04 00:00:00
Last date of month : 30