Converting string into DateTime in Python

Last Updated : 01 May, 2025

The goal is to convert a date string like "2021/05/25" into a Python-recognized DateTime object such as 2021-05-25 00:00:00. This enables accurate and consistent date operations like comparisons, calculations and formatting when working with time-related data from sources like files or user input. Let's understand how to do this efficiently.

Using dateutil.parser.parse()

parse() function from the dateutil library automatically detects and converts a wide range of date string formats into a datetime object. This method is ideal when your input dates are inconsistent or come from user input or APIs.

Python

from dateutil.parser import parse

s = '2023-07-25'
res = parse(s)
print(res)

Output

2023-07-25 00:00:00

Explanation: Here, we passed the date string '2023-07-25' to parse(). It automatically recognized the format and returned a full datetime object.

Using datetime.strptime()

datetime.strptime() method, part of Python's datetime module, efficiently converts a date string into a DateTime object when the exact format is known, requiring a format specification like '%Y/%m/%d'.

Python

import datetime

s = '2021/05/25'
format = '%Y/%m/%d'
res = datetime.datetime.strptime(s, format)
print(res)

Output

2021-05-25 00:00:00

Explanation: We define the exact format (%Y/%m/%d) for the input string '2021/05/25' and strptime() converts it into a datetime object.

Using pandas.to_datetime()

For large datasets, especially in CSV or Excel format, pandas.to_datetime() efficiently converts multiple date strings into DateTime objects, handling various formats, missing values, and errors.

Python

import pandas as pd

s = ['2021-05-25', '2020/05/25', '2019/02/15']
res = pd.to_datetime(s, format='mixed')
print(res)

Output

DatetimeIndex(['2021-05-25', '2020-05-25', '2019-02-15'], dtype='datetime64[ns]', freq=None)

Explanation: pandas.to_datetime() automatically detects the correct format for each date in the list using format='mixed'. This avoids format mismatch errors.

Using datetime.date()

For cases where you only need the date (without time), you can use datetime.strptime() followed by date() to convert the string into a DateTime object and extract the date. This method is still quite efficient but slightly more verbose than parse() or to_datetime().

Python

import datetime

s = '2021/05/25'
format = '%Y/%m/%d'
res = datetime.datetime.strptime(s, format).date()
print(res)

Output

2021-05-25

Explanation: After converting the string to a datetime object, we call .date() to extract just the date.

Similar Reads:
Convert string to DateTime and vice-versa in Python
Manipulate Date and Time with the Datetime Module
Create Python Datetime from string
Working with Datetime Objects and Timezones in Python
Introduction to Python Dateutil Package
datetime.strptime()
pandas.to_datetime()