Python| datetime.timedelta()函数

Python timedelta()函数存在于datetime 库下，该库通常用于计算日期的差异，也可用于Python中的日期操作。这是执行日期操作的最简单方法之一。

Syntax : datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)

Returns : Date

代码#1：

# Timedelta function demonstration 
  
from datetime import datetime, timedelta
  
  
# Using current time
ini_time_for_now = datetime.now()
  
# printing initial_date
print ("initial_date", str(ini_time_for_now))
  
# Calculating future dates
# for two years
future_date_after_2yrs = ini_time_for_now + \
                        timedelta(days = 730)
  
future_date_after_2days = ini_time_for_now + \
                         timedelta(days = 2)
  
# printing calculated future_dates
print('future_date_after_2yrs:', str(future_date_after_2yrs))
print('future_date_after_2days:', str(future_date_after_2days))

输出：

initial_date 2019-02-27 12:41:45.018389
future_date_after_2yrs: 2021-02-26 12:41:45.018389
future_date_after_2days: 2019-03-01 12:41:45.018389

代码#2：

# Timedelta function demonstration 
from datetime import datetime, timedelta
  
  
# Using current time
ini_time_for_now = datetime.now()
  
# printing initial_date
print ("initial_date", str(ini_time_for_now))
  
# Calculating past dates
# for two years
past_date_before_2yrs = ini_time_for_now - \
                       timedelta(days = 730)
  
# for two hours
past_date_before_2hours = ini_time_for_now - \
                        timedelta(hours = 2)
  
  
# printing calculated past_dates
print('past_date_before_2yrs:', str(past_date_before_2yrs))
print('past_date_after_2days:', str(past_date_before_2hours))

输出：

initial_date 2019-02-27 12:41:46.104662
past_date_before_2yrs: 2017-02-27 12:41:46.104662
past_date_after_2days: 2019-02-27 10:41:46.104662

代码#3：

# Timedelta function demonstration 
from datetime import datetime, timedelta
  
# Using current time
ini_time_for_now = datetime.now()
  
# printing initial_date
print ("initial_date", str(ini_time_for_now))
  
# Some another datetime
new_final_time = ini_time_for_now + \
                 timedelta(days = 2)
  
# printing new final_date
print ("new_final_time", str(new_final_time))
  
  
# printing calculated past_dates
print('Time difference:', str(new_final_time - \
                             ini_time_for_now))

输出：

initial_date 2019-02-27 12:41:47.386595
new_final_time 2019-03-01 12:41:47.386595
Time difference: 2 days, 0:00:00