(16)Python日期和时间

日期及其各个部分用不同的日期时间函数表示。 此外，还有格式说明符，它们在显示日期的字母部分(如月份或星期几的名称)中发挥作用。 以下代码显示了今天的日期和日期的各个部分。

import datetime

print 'The Date Today is  :', datetime.datetime.today()

date_today = datetime.date.today()
print (date_today)
print ('This Year   :', date_today.year)
print ('This Month    :', date_today.month(
print ('Month Name:',date_today.strftime('%B'))
print ('This Week Day    :', date_today.day))
print ('Week Day Name:',date_today.strftime('%A'))
Python

执行上面示例代码，得到以下结果 –

The Date Today is  : 2018-05-22 15:38:35.835000
2018-05-22
This Year   : 2018
This Month    : 4
Month Name: May
This Week Day    : 22
Week Day Name: Sunday
Shell

对于涉及日期的计算，我们将各种日期存储到变量中，并将相关的数学运算符应用于这些变量。

import datetime 

#Capture the First Date
day1 = datetime.date(2018, 2, 12)
print ('day1:', day1.ctime())

# Capture the Second Date
day2 = datetime.date(2017, 8, 18)
print ('day2:', day2.ctime())

# Find the difference between the dates
print ('Number of Days:', day1-day2)


date_today  = datetime.date.today() 

# Create a delta of Four Days 
no_of_days = datetime.timedelta(days=4) 

# Use Delta for Past Date
before_four_days = date_today - no_of_days 
print ('Before Four Days:', before_four_days )

# Use Delta for future Date
after_four_days = date_today + no_of_days 
print 'After Four Days:', after_four_days
Python

执行上面示例代码，得到以下结果 –

day1: Mon Feb 12 00:00:00 2018
day2: Fri Aug 18 00:00:00 2017
Number of Days: 178 days, 0:00:00
Before Four Days: 2018-04-18
After Four Days: 2018-04-26
Shell

日期和时间使用逻辑运算符进行比较。必须小心将日期的正确部分进行比较。 在下面的例子中，我们采用未来和过去的日期，并使用python if子句和逻辑运算符进行比较。

import datetime

date_today  = datetime.date.today() 

print ('Today is: ', date_today)
# Create a delta of Four Days 
no_of_days = datetime.timedelta(days=4) 

# Use Delta for Past Date
before_four_days = date_today - no_of_days 
print ('Before Four Days:', before_four_days )

after_four_days =  date_today + no_of_days

date1 = datetime.date(2018,4,4)

print ('date1:',date1)

if date1 == before_four_days :
    print ('Same Dates')
if date_today > date1:
    print ('Past Date')
if date1 < after_four_days:
    print ('Future Date')
Python

执行上面示例代码，得到以下结果 –

Today is:  2018-04-22
Before Four Days: 2018-04-18
date1: 2018-04-04
Past Date
Future Date
Shell