How To Comment In Python: A Guide to Effective Code Documentation

Comments in Python play a crucial role in enhancing code readability and providing valuable insights for developers.

They are non-executable lines that are ignored by the Python interpreter but serve as explanatory notes for programmers.

In this guide, we'll explore the various ways to add comments in Python and best practices for effective code documentation.

1. Single-line Comments:

The most straightforward way to add a comment in Python is to use the hash (#) symbol. Anything following the hash on the same line is treated as a comment.

# This is a single-line comment
print("Hello, World!")  # This comment explains the print statement

Single-line comments are ideal for brief explanations or annotations.

2. Multi-line Comments:

Python does not have a built-in syntax for multi-line comments. However, developers often use triple-quotes (''' or """) to create multiline strings, effectively serving as multi-line comments.

This is a multi-line comment.
It spans multiple lines and is enclosed by triple-quotes.
print("Python is amazing!")

While this approach works, it's not the conventional way to add comments. The preferred method is to use the triple-quotes for docstrings, which are used for function and module documentation.

3. Docstrings:

Docstrings are special strings used for documenting modules, classes, functions, and methods. They are enclosed by triple-quotes and are accessible at runtime.

3.1 Function Docstring:

def add_numbers(a, b):
    Adds two numbers and returns the result.

    a (int): The first number.
    b (int): The second number.

    int: The sum of the two numbers.
    return a + b

3.2 Module Docstring:

This module provides utility functions for mathematical operations.

4. Commenting Best Practices:

  1. Be Clear and Concise: Comments should be clear and concise, providing valuable information without unnecessary details.

  2. Avoid Redundancy: Don't comment on things that are obvious from the code. Comments should add insights that are not immediately evident.

  3. Keep Comments Updated: As code evolves, make sure to update comments accordingly. Outdated comments can be misleading.

  4. Use Descriptive Variable and Function Names: Well-named variables and functions reduce the need for excessive comments. A self-explanatory name is often better than a comment.

. Comment Why, Not What: Focus on explaining the "why" behind a piece of code rather than reiterating what the code does.


Comments in Python are essential for maintaining code clarity and facilitating collaboration among developers.

By using single-line comments, multi-line comments, and docstrings appropriately, you can create well-documented code that is easy to understand and maintain.

Adopting best practices for commenting ensures that your comments remain valuable assets throughout the development lifecycle.