Python How to Convert String to Datetime Easily

Use datetime.strptime(your_string, format) from the datetime module to convert a string to a datetime object in Python.

Examples

Input"2024-06-01"

Outputdatetime.datetime(2024, 6, 1, 0, 0)

Input"01/06/2024 14:30"

Outputdatetime.datetime(2024, 6, 1, 14, 30)

Input"June 1, 2024 2:30 PM"

Outputdatetime.datetime(2024, 6, 1, 14, 30)

How to Think About It

To convert a string to a datetime, first identify the exact format of the date and time in the string. Then use the strptime function with a matching format string to parse it into a datetime object.

Algorithm

1

Get the input string representing the date and time.

2

Determine the format pattern that matches the string (e.g., year-month-day).

3

Use the datetime module's strptime function with the string and format.

4

Return the resulting datetime object.

Code

python

from datetime import datetime

# Example string
date_string = "2024-06-01 14:30"

# Convert string to datetime
converted_date = datetime.strptime(date_string, "%Y-%m-%d %H:%M")

print(converted_date)

Output

2024-06-01 14:30:00

Dry Run

Let's trace converting '2024-06-01 14:30' to datetime

1

Input string

"2024-06-01 14:30"

2

Format string

"%Y-%m-%d %H:%M"

3

Result

datetime.datetime(2024, 6, 1, 14, 30)

Step	Value
Input string	2024-06-01 14:30
Format string	%Y-%m-%d %H:%M
Output datetime	2024-06-01 14:30:00

Why This Works

Step 1: Import datetime module

We import datetime to access date and time functions.

Step 2: Use strptime function

strptime reads the string and converts it to a datetime object using the given format.

Step 3: Format string matches input

The format string uses codes like %Y for year and %m for month to match the input string exactly.

Alternative Approaches

Using dateutil.parser.parse

python

from dateutil.parser import parse

date_string = "June 1, 2024 2:30 PM"
converted_date = parse(date_string)
print(converted_date)

This method automatically detects the format but requires installing the dateutil package.

Using pandas.to_datetime

python

import pandas as pd

date_string = "2024-06-01 14:30"
converted_date = pd.to_datetime(date_string)
print(converted_date)

Pandas can parse many formats easily but adds a dependency and returns a Timestamp object.

Complexity: O(1) time, O(1) space

Time Complexity

Parsing a fixed-length string with strptime takes constant time, as it processes each character once.

Space Complexity

The function uses a fixed amount of memory to store the datetime object, so space is constant.

Which Approach is Fastest?

Using datetime.strptime is fastest and built-in, while dateutil.parser.parse is slower but more flexible.

Approach	Time	Space	Best For
datetime.strptime	O(1)	O(1)	Known fixed formats, fastest
dateutil.parser.parse	O(n)	O(1)	Unknown or varied formats, flexible
pandas.to_datetime	O(n)	O(1)	Data analysis with pandas, many formats