Formatting Dates in Python

In different regions of the world, different types of date formats are used and for that reason usually, programming languages provide a number of date formats for the developed to deal with. In Python, it is dealt with by using a liberty called DateTime. It consists of classes and methods that can be used to work with data and time values. 

Required library 

import datetime

The datetime.time method

Time values can be represented using the time class. The attributes for the time class include the hour, minute, second, and microsecond.

Syntax of datetime.time

time(hour, minute, second, microsecond)

Example 1:

import datetime

tm = datetime.time(2, 25, 50, 13)
print(tm)

Output

02:25:50.000013

Example 2:

There are ranges for the time attributes i.e for seconds we have the range between 0 to 59 and for nanoseconds, range is between 0 to 999999. If the range exceeds, the compiler shows a ValueError. The instance of time class consists of three instance attributes namely hour, minute, second, and microsecond. These are used to get specific information about the time. 

import datetime

tm = datetime.time(1, 50, 20, 133257)

print('Time tm is ',
 tm.hour, ' hours ',
 tm.minute, ' minutes ',
 tm.second, ' seconds and ',
 tm.microsecond, ' microseconds')

Output

Time tm is 1 hours 50 minutes 20 seconds and 133257 microseconds

The datetime.date method

The values for the calendar date can be represented via the date class. The date instance consists of attributes for the year, month, and day. 

Syntax of datetime.date

date(yyyy, mm, dd)

Example 1:

import datetime

date = datetime.date(2018, 5, 12)
print('Date date is ', date.day,
 ' day of ', date.month,
 ' of the year ', date.year)

Output

Date date is 12 day of 5 of the year 2018

Example 2:

To get today's date names a method called today() is used and to get all the information in one object (today's information) ctime() method is used. 

import datetime

tday = datetime.date.today()
daytoday = tday.ctime()

print("The date today is ", tday)
print("The date info. is ", daytoday)

Output

The date today is 2020-01-30
The date info. is Thu Jan 30 00:00:00 2020

Convert string to date using DateTime

Conversion from string to date is many times needed while working with imported data sets from a CSV or when we take inputs from website forms. To do this, Python provides a method called strptime(). 

Syntax: datetime.strptime(string, format)

Parameters:

• string - The input string.
• format - This is of string type. i.e. the directives can be embedded in the format string.

Example:

from datetime import datetime

print(datetime.strptime('5/5/2019',
 '%d/%m/%Y'))

Output

2019-05-05 00:00:00

Convert dates to strings using DateTime

Date and time are different from strings and thus many times it is important to convert the DateTime to string. For this, we use strftime() method. 

Syntax of datetime.strftime

Syntax: datetime.strftime(format, t)

Parameters:

• format - This is of string type. i.e. the directives can be embedded in the format string.
• t - the time to be formatted.

Example 1:

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)

print(x.strftime("%b %d %Y %H:%M:%S"))

Output 

May 12 2018 02:25:50

Example 2:

The same example can also be written in a different place by setting up the print() method. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)

print(x.strftime("%H:%M:%S %b %d %Y"))

Output 

02:25:50 May 12 2018 

%H, %M and %S displays the hour, minutes and seconds respectively. %b, %d and %Y displays 3 characters of the month, day and year respectively. Other than the above example the frequently used character code List along with its functionality are:

Frequently used character code in DateTime

• %a: Displays three characters of the weekday, e.g. Wed. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%a"))

Output

Sat

• %A: Displays name of the weekday, e.g. Wednesday. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%A"))

Output

Saturday

• %B: Displays the month, e.g. May. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%B"))

Output

May

• %w: Displays the weekday as a number, from 0 to 6, with Sunday being 0. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%w"))

Output

6

• %m: Displays month as a number, from 01 to 12. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%m"))

Output

5

• %p: Define AM/PM for time. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%p"))

Output

PM

• %y: Displays year in two-digit format, i.e "20" in place of "2020". 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("% y"))

Output

18

• %f: Displays microsecond from 000000 to 999999. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("% f"))

Output

000013

• %j: Displays number of the day in the year, from 001 to 366. 

import datetime

x = datetime.datetime(2018, 5, 12, 2, 25, 50, 13)
print(x.strftime("%j"))

Output

132