Python Date and Time (datetime)

In this article, you will learn how to manipulate dates and times in Python through examples.

Python has a module nameddatetimemodule, used for processing dates and times. Before we delve deeper, let's create some simple programs related to dates and times.

示例1to get the current date and time

import datetime
datetime_object　=　datetime.datetime.now()
print(datetime_object)

When you run the program, the output will be similar to:

2020-04-13　17:09:49.015911

Here, we use the import datetime statement to importdatetimemodule.

A class defined in the datetime module is the datetime class. Then, we use the now() method to create a datetime object containing the current local date and time.

示例2: Get current date

import datetime
date_object = datetime.date.today()
print(date_object)

When you run the program, the output will be similar to:

2020-04-13

In this program, we used the today() method defined in the date class to get a date object containing the current local date.

What's inside datetime?

We can usedir()function to get a list of all module attributes.

import datetime
print(dir(datetime))

The output when running the program is:

['MAXYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_divide_and_round', 'date', 'datetime', 'datetime_CAPI', 'time', 'timedelta', 'timezone', 'tzinfo']

Common classes in the datetime module are:

• date class

• time class

• datetime class

• timedelta class

datetime.date class

You can instantiate a date object from the date class. The date object represents a date (year, month, and day).

示例3: Represents a Date object

import datetime
d = datetime.date(2019,　4,　13:",　s
print(d)

The output when running the program is:

2019-04-13

If you are curious, the date() in the above example is the constructor of the date class. The constructor has three parameters: year, month, and day.

variableais a date object.

We can only import the date class from the datetime module. It is like this:

from datetime import date
a = date(2019,　4,　13:",　s
print(a)

示例4: Get current date

You can use a class method named today() to create a date object containing the current date. The method is as follows:

from datetime import date
today = date.today()
print("Current date =", today)

示例5: Get date from timestamp

We can also create a date object from a timestamp. Unix timestamp is the number of seconds from a specific date to UTC1970 years1month1seconds between two days. You can use the fromtimestamp() method to convert a timestamp to a date.

from datetime import date
timestamp = date.fromtimestamp(1576244364:",　s
print("date =", timestamp)

The output when running the program is:

date =　2019-12-13

示例6Printing today's year, month, and day

We can easily get the year, month, day, day of the week, etc. from the date object. It is like this:

from datetime import date
# Today's date object
today = date.today()　
print("Current year:", today.year)
print("Current month:", today.month)
print("Current day:", today.day)

datetime.time

Time objects instantiated from the time class represent local time.

示例7Time object representing the time

from datetime import time
# time(hour = 0, minute = 0, second = 0)
a = time()
print("a =", a)
# time(hour, minute and second)
b = time(11,　34,　56:",　s
print("b =", b)
# time(hour, minute and second)
c = time(hour =　11, minute =　34, second =　56:",　s
print("c =", c)
# time(hour, minute, second, microsecond)
d = time(11,　34,　56,　234566:",　s
print("d =", d)

The output when running the program is:

a = 00:00:00
b =　11:34:56
c =　11:34:56
d =　11:34:56.234566

示例8Printing time, minute, second, and microsecond

After creating the time object, you can easily print its properties, such ashour,minuteetc.

from datetime import time
a = time(11,　34,　56:",　s
print("hour=", a.hour)
print("minute=", a.minute)
print("second=", a.second)
print("microsecond=", a.microsecond)

When running the example, the output will be:

hour=　11
minute=　34
second=　56
microsecond= 0

Note that we have not passedmicrosecondTherefore, it will print the default value 0.

datetime.datetime

The datetime module has a class named date that can contain parameters fromdateandtimeinformation of the object.

示例9Python datetime object

from datetime import datetime
# datetime(year, month, day)
a = datetime(2019,　11,　28:",　s
print(a)
# datetime(year, month, day, hour, minute, second, microsecond)
b = datetime(2019,　11,　28,　23,　55,　59,　342380)
print(b)

The output when running the program is:

2019-11-28　00:00:00
2019-11-28　23:55:59.342380

The first three parameters year, month, and day of the datetime() constructor are required.

示例10Print year, month, hour, minute and timestamp

from datetime import datetime
a = datetime(2019,　12,　28,　23,　55,　59,　342380)
print("Year = ", a.year)
print("Month = ", a.month)
print("Day = ", a.day)
print("Hour = ", a.hour)
print("Month = ", a.minute)
print("Timestamp = ", a.timestamp())

The output when running the program is:

Year =　2019
Month =　12
Day =　28
Hour =　23
Month =　55
Timestamp =　1577548559.34238

datetime.timedelta

timedelta objects represent the time difference between two dates or times.

示例11The time difference between two dates and times

from datetime import datetime, date
t1　=　2018, month =　7, day =　12:",　s
t2　=　2017, month =　12, day =　23:",　s
t3　=1　-　t2
print("t3　= "3:",　s
t4　=　2018, month =　7, day =　12, hour =　7, minute =　9, second =　33:",　s
t5　=　2019, month =　6, day =　10, hour =　5, minute =　55, second =　13:",　s
t6　=4　-　t5
print("t6　= "6:",　s
print("type of t3　=3))　
print("type of t6　=6))

The output when running the program is:

t3　=　201　days, 0:00:00
t6　=　-333　days,　1:14:20
type of t3　=
type of t6　=

Note thatt3andt6are of type <class 'datetime.timedelta'>.

示例12The time difference between two timedelta objects

from datetime import timedelta
t1　=　2, days =　5hours =　1,　seconds　=　33:",　s
t2　=　4hours =　11, minutes =　4,　seconds　=　54:",　s
t3　=1　-　t2
print("t3　= "3:",　s

The output when running the program is:

t3　=　14　days,　13:55:39

Here, we create two timedelta objectst1andt2The number of days directly between them is printed on the screen.

示例13Print negative timedelta objects

from datetime import timedelta
t1　=　33:",　s
t2　=　54:",　s
t3　=1　-　t2
print("t3　= "3:",　s
print("t3　= "3))

The output when running the program is:

t3　=　-1　day,　23:59:39
t3　= 0:00:21

示例14Duration (in seconds)

You can use the total_seconds() method to get the total number of seconds in a timedelta object.

from datetime import timedelta
t = timedelta(days =　5hours =　1,　seconds　=　33,　seconds =　233423:",　s
,　microseconds =

The output when running the program is:

print("total seconds =", t.total_seconds())　435633.233423

total seconds =+You can also use

operator finds the sum of two dates and times. Similarly, you can multiply timedelta objects by integers and floating-point numbers.

Python format date and time / #　mm / The representation of dates and times may vary in different places, organizations, etc. In the United States, mm is used / #　dd / yyyy is more common, while in the UK dd is used

yyyy is more common.

Python strftime()-Python has strftime() and strptime() methods to handle this issue.

String date and time object

示例15strftime() method is defined under the date, datetime, and time classes. This method creates a formatted string based on the given date, datetime, or time object.

from datetime import datetime
：使用strftime()格式化日期
#　current　date　and　time
now　=　datetime.now()
t　=　now.strftime("%H:%M:%S")
s1　print("time:",　t)/%d/=　now.strftime("%d
=　now.strftime("%m/#　mm/mm
YY　H:M:S　format1print("s1:",　s
s2　dd/%m/=　now.strftime("%d
%Y,　%H:%M:%S")/#　dd/mm
YY　H:M:S　format2print("s2:",　s

When you run the program, the output will be similar to:

)4:34:52
s1:　12/26/2018time:　04:34:52
s2:　26/12/2018time:　04:34:52

,　0

In the above program,t,s1ands2is a string.

• %Y -years [0001,...2018,2019,...9999]

• %m -months [01,02,...11,12]

• %d -days [01,02,...30,31]

• %H -hours [00, 01,...22,23

• %M -minutes [00, 01,...58,59]

• %S -seconds [00, 01,...58,59]

For more information on strftime() code and setting its format, please visit:Python strftime().

Python strptime()-Date and time string

strptime() method creates a datetime object from a given string (representing a date and time).

示例16：strptime()

from datetime import datetime
date_string = "21　June,　2018"
print("date_string =", date_string)
date_object = datetime.strptime(date_string, '%d %B, %Y')
print("date_object =", date_object)

The output when running the program is:

date_string =　21　June,　2018
date_object =　2018-06-21　00:00:00

The strptime() method has two parameters:

1. String representing date and time

2. Is equivalent to the format code of the first parameter

By the way, the %d, %B, and %Y format codes are used for day, month (full name), and year, respectively.

VisitPython strptime()For more information.

Handling time zones in Python

Assuming you are working on a project that needs to display the date and time according to its time zone. We recommend using third-partypytz moduleInstead of handling the time zone yourself.

from datetime import datetime
import pytz
local = datetime.now()
print("Local:", local.strftime("%m/%d/"%Y, %H:%M:%S")
tz_NY = pytz.timezone('America/New_York')　
datetime_NY = datetime.now(tz_NY)
print("NY:", datetime_NY.strftime("%m/%d/"%Y, %H:%M:%S")
tz_London = pytz.timezone('Europe/London')
datetime_London = datetime.now(tz_London)
print("London:", datetime_London.strftime("%m/%d/"%Y, %H:%M:%S")

When you run the program, the output will be similar to:

Local time:　2018-12-20　13:10:44.260462
America/New_York time:　2018-12-20　13:10:44.260462
Europe/London time:　2018-12-20　13:10:44.260462

Here,datetime_NYanddatetime_LondonIs a datetime object containing the current date and time with their respective time zones.