How to Convert a String to a Date in Python

John on June 28, 2021

To convert a string to a date object in Python, import the datetime package and use the striptime() function. Pass the date to convert as the first argument and the format as the second.

Let's look at an example of changing a date string in a typical format to a Python date object.

from datetime import datetime

date_string = '28/07/2021 16:25:39'

date_object = datetime.strptime(date_string, '%d/%m/%Y %H:%M:%S')

print(date_object)
print(type(date_object))

2021-07-28 16:25:39
<class 'datetime.datetime'>

By wrapping the output in the Python type() function we can see the type class is now datetime.datetime.

The important thing to observe is that the input date string is formatted according to the format described in the second argument of striptime(). If these two are mismatched you will get a ValueError exception. Here an example to show this mistake:

date_string = '2021'

date_object = datetime.strptime(date_string, '%y')

print(date_object)

ValueError: unconverted data remains: 21

This happens because %y does not represent a four-digit year; %Y (uppercase) does, however.

from datetime import datetime

date_string = '2021'

date_object = datetime.strptime(date_string, '%Y')

print(date_object)

2021-01-01 00:00:00