Adventures in Machine Learning

The Importance of Commenting Python Code for Readability and Maintainability

Why Comments are Crucial in Python Programming

In the world of Python programming, commenting your code should be considered an essential part of your development process. It allows for the easy understanding of your codebase and the functionality of specific components.

In this article, we’ll explore the different types of comments available in Python, their syntax and format, and the best practices for writing them.

The Need for Comments in Python Code

Comments make it easier for others to understand your code, especially if it’s a team project. It’s not enough to have code that works, but you need code that is easy to maintain, modify, and debug.

Code that is overly complex or convoluted can be overwhelming to understand and modify, especially if there are no comments available. Comments can clarify your thoughts and help you avoid mistakes while coding.

It’s an excellent way to support the reasoning behind why you chose a particular solution to a problem. When it comes to working with unfamiliar code or large codebases, the presence of comments makes the difference between understanding the code or not.

Types of Comments in Python

Inline Comments:

Inline comments are single-line explanations that sit on the same line as the code they’re commenting. They’re typically used to make minor comments related to the code in question.

Inline comments are good for immediate feedback, but their usage should be minimal. Block Comments:

Block comments are a series of single-line comments grouped together.

They’re typically used to provide insight into particular blocks of code. Block comments provide more extended commentaries that span across multiple lines relating to the purpose of the code in question.

Multi-Line Comments:

Multi-line comments are comments that span across multiple lines, either to provide in-depth details or entire explanations of the code’s functionality. It’s commonly used to describe what a code block does or the intention of a script’s programming.

Docstring Comments:

Docstring comments are used at the beginning of class, function, constructor, or method definitions. They’re enclosed in triple quotes and should provide a detailed description of the class, function, or method.

Docstring comments are essential because they’re used to generate technical documentation automatically.

Guidelines for Writing Comments

Short: The purpose of comments is to help clarify code. Writing long and detailed comments can become cumbersome and may reduce the overall readability of the code.

So it’s essential to keep your comments short and to the point. Straightforward: Your comments should make it easy for others to understand your code.

Comments should convey the logic of the code in a way that is easy to grasp. Relevant: Avoid making comments that don’t relate to the code.

You don’t want to add ambiguity to your code by making irrelevant comments. Sensible: Write comments that make sense and are practical.

Avoid cryptic comments that leave others confused and result in code misinterpretation. Valuable: Provide value to your comments.

Your comments should add something that’s not already visible or evident in code. It should give context or additional information.

Commenting Out Code for Testing

Sometimes when debugging code, it’s necessary to comment out specific lines of code to locate the exact point of an error. For instance, if the result of a program isn’t what you expected, commenting out sections of the codebase can help you locate and fix a runtime error.

Commenting out code should only be temporary and should be removed when you’re done debugging the code.

Syntax and Format of Comments in Python

Comment Symbol in Python:

One of the primary ways to comment code in Python is with the hash symbol(#). Anything that appears after the hash symbol in the same line is treated as a comment in Python.

Single-Line Comments in Python:

Single-line comments are indicated by the hash symbol (#) and can be used anywhere in the code to make minor comments or clarifications. Multi-Line Comments in Python:

Multi-line comments are indicated by enclosing the comment block within triple quotes.

This feature is provided by Python’s flexibility with string literals.

Docstring Comments in Python

Docstring comments should be used to document classes, functions, constructors, or methods. It should be enclosed in triple quotes and should immediately follow the method signature.


In conclusion, understanding the importance of commenting Python code and the available types of comments and their formats is essential to creating effective, readable, and maintainable code. The most commendable comment is one that balances being informative, clear, concise, and consistent with the code logic while being relevant and practical.

Commenting code may seem like an extra effort, but it ultimately pays off in time, architecture, and development maintainability.

3) Best Practices for Writing Comments in Python

Writing comments in Python code can be quite beneficial if done correctly. It helps to improve the readability and the maintainability of your code to ensure that it remains relevant and practical long after you have written it.

Here are some best practices for writing comments in Python.

Importance of Indentations in Comments

It’s essential to have uniform indentations in your comments that match the code it refers to. This practice enhances the readability of the code, making it easier for developers to spot errors and understand the code.

It’s crucial to ensure that the indentations in the comments match the indentations in the code, making it easy to find the relevant code that comments refer to.

Correct Scenarios for Adding Comments

Comments are an excellent way to add clarity and additional information to your codebase. Adding comments to your code should not be a time-consuming task.

It should be done sparingly and only when necessary. It’s essential to provide a broad overview of the code and divide it into sections with inline comments.

Inline comments should only be used when explaining specific functions or decision points within the code. Comments also provide meaning to the constants and variables used in the code.

Conventions for Writing Good Documentation Strings

Documentation Strings, Docstrings, are used to generate documentation for modules, functions, classes, and methods. Docstrings provide meaningful context and allow for the auto-generation of API reference guides, providing developers with insights into your code.

Python Enhancement Proposal (PEP) 257 defines the conventions for writing good docstrings in Python. Docstrings should be enclosed in triple-quotes to indicate the beginning and end of the docstring.

For public modules, functions, classes, and methods, their docstrings should contain a summary line that gives a brief overview of what the object does.

4) Benefits of Writing Comments in Python Programming

Adding comments to your code has several benefits that go beyond the code’s readability. It’s essential to write quality comments that promote better collaboration with your colleagues and improve the application’s overall quality.

Here are some key benefits of writing comments in Python programming.

Improving Code Quality

Adding comments to your code increases your code’s quality. Python code is typically subjected to code reviews, and having quality comments improves the efficiency of code reviews.

By having comments that explain your code’s intention and functionality, you give reviewers a better understanding of your code, and they can make informed decisions about possible improvements, changes, or errors that need fixing.

Finding and Fixing Errors

Comments can also be used to locate and fix errors in your code. During debugging, you can comment out lines of code to see if it fixes a particular error.

If the error is fixed, then the problem is most likely contained in one of the commented lines of code. By narrowing down the source of the error to one particular block of code, developers can quickly solve the problem.


Comments also aid in creating reusable code. Reusable code saves developers time and effort when developing new applications.

By writing quality comments, developers can reuse code modules without having to worry about those code modules’ functionality. Code reusability is beneficial because it reduces the overall time and effort spent on developing an application.

Collaboration and Teamwork in Python Programming

One of the advantages of having well-commented code is better collaboration within a development team. Comments allow team members to work together more efficiently to solve problems and develop new features.

By providing more detail and context, comments give developers a clearer understanding of the code. This understanding facilitates better communication, planning, and progress tracking.

In conclusion, comments play a crucial role in ensuring that your Python code is readable, maintainable, and of high quality. Best practices such as matching code indentations in comments, adding relevant comments, and using conventions for writing good documentation strings are essential for writing quality comments.

The benefits of commenting include improving code quality, finding and fixing errors, supporting code reusability, and promoting better collaboration within a development team. In summary, commenting in Python programming is a critical component of creating readable, maintainable, and high-quality code.

To write effective comments, best practices include indentations that match the code, adding comments only when necessary, and following conventions for docstring comments. The benefits of commenting include improving code quality, finding and fixing errors, supporting code reusability, and promoting better collaboration within a development team.

By taking the time to write quality comments, Python developers can save time, reduce errors, and work more collaboratively with others. Always remember to keep your comments relevant, concise, and valuable, and your code will become more readable and maintainable, saving time and effort in the long run.

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