Of course! Working with datetime objects and their string representations is a fundamental task in Python. Here’s a comprehensive guide covering conversion, formatting, and parsing.

The Core Idea: Two Operations

1. Formatting: Converting a datetime object into a string. You control the format.
2. Parsing (or Strptime): Converting a string into a datetime object. You must describe the format of the string.

Formatting a datetime Object to a String (strftime)

To format a datetime object as a string, you use the .strftime() method. The name stands for "string format time".

Syntax: datetime_object.strftime(format_code)

The format_code is a string containing special directives (starting with ) that represent different parts of the date and time.

Common Format Codes

Example: strftime

import datetime
# 1. Create a datetime object
now = datetime.datetime.now()
print(f"Original datetime object: {now}")
# Example output: Original datetime object: 2025-10-27 10:30:55.123456
# 2. Format it into different string representations
# Standard ISO 8601 format
iso_format = now.strftime("%Y-%m-%d %H:%M:%S")
print(f"ISO Format: {iso_format}")
# Example output: ISO Format: 2025-10-27 10:30:55
# More readable format
readable_format = now.strftime("%B %d, %Y at %I:%M %p")
print(f"Readable Format: {readable_format}")
# Example output: Readable Format: October 27, 2025 at 10:30 AM
# Another common format
file_name_format = now.strftime("%Y%m%d_%H%M%S")
print(f"Filename Format: {file_name_format}")
# Example output: Filename Format: 20251027_103055

Parsing a String into a datetime Object (strptime)

To parse a string into a datetime object, you use the datetime.datetime.strptime() function. The name stands for "string parse time".

Syntax: datetime.datetime.strptime(date_string, format_code)

• date_string: The string you want to convert.
• format_code: The format that the date_string is in. This must match the string exactly.

Example: strptime

import datetime
# The string we want to parse
date_string = "2025-10-27 15:45:30"
# The format of that string
format_code = "%Y-%m-%d %H:%M:%S"
# Parse the string into a datetime object
parsed_datetime = datetime.datetime.strptime(date_string, format_code)
print(f"Original string: '{date_string}'")
print(f"Parsed datetime object: {parsed_datetime}")
print(f"Type of parsed object: {type(parsed_datetime)}")

Output:

Original string: '2025-10-27 15:45:30'
Parsed datetime object: 2025-10-27 15:45:30
Type of parsed object: <class 'datetime.datetime'>

Parsing a More Complex String

# A more complex example with a timezone offset
tz_string = "2025-12-25 09:00:00-0500"
# The format code must match the string, including the timezone offset
tz_format_code = "%Y-%m-%d %H:%M:%S%z"
# Note: Python 3.7+ handles %z correctly. In older versions, it might be tricky.
parsed_tz_datetime = datetime.datetime.strptime(tz_string, tz_format_code)
print(f"\nOriginal string: '{tz_string}'")
print(f"Parsed datetime object: {parsed_tz_datetime}")
print(f"Timezone info: {parsed_tz_datetime.tzinfo}")

Output:

Original string: '2025-12-25 09:00:00-0500'
Parsed datetime object: 2025-12-25 09:00:00-05:00
Timezone info: UTC-05:00

The Modern Alternative: fromisoformat and isoformat

For the very common ISO 8601 format (e.g., YYYY-MM-DDTHH:MM:SS), Python 3.7+ provides simpler, more direct methods.

datetime.fromisoformat()

Parses a string in ISO format into a datetime object.

import datetime
iso_string = "2025-10-27T10:30:55.123456"
# Use the dedicated method
dt_object = datetime.datetime.fromisoformat(iso_string)
print(f"ISO String: {iso_string}")
print(f"Parsed object: {dt_object}")

Output:

ISO String: 2025-10-27T10:30:55.123456
Parsed object: 2025-10-27 10:30:55.123456

datetime_object.isoformat()

Formats a datetime object into an ISO format string.

import datetime
dt_object = datetime.datetime.now()
# Use the dedicated method
iso_string = dt_object.isoformat()
print(f"Original datetime: {dt_object}")
print(f"ISO String: {iso_string}")

Output:

Original datetime: 2025-10-27 10:31:00.654321
ISO String: 2025-10-27T10:31:00.654321

Handling Dates (without Time)

If you only care about the date part, it's best to use the datetime.date class. It has its own .strftime() and datetime.strptime() methods.

import datetime
# --- Formatting a date object ---
today = datetime.date.today()
print(f"Original date object: {today}")
# Format as a string
date_string = today.strftime("%A, %B %d, %Y")
print(f"Formatted date string: {date_string}")
# Example output: Friday, October 27, 2025
# --- Parsing a string into a date object ---
date_string_to_parse = "15-Aug-1990"
# The format code must match
format_code_for_date = "%d-%b-%Y"
parsed_date = datetime.datetime.strptime(date_string_to_parse, format_code_for_date).date()
print(f"\nParsed date string: '{date_string_to_parse}'")
print(f"Parsed date object: {parsed_date}")
print(f"Type: {type(parsed_date)}")

Output:

Original date object: 2025-10-27
Formatted date string: Friday, October 27, 2025
Parsed date string: '15-Aug-1990'
Parsed date object: 1990-08-15
Type: <class 'datetime.date'>

Summary Table