If you have struggled reading the code written by somebody else (or your own code after a couple of years), you know the importance of adding comments to your code.
Comments are notes or entries added to the source code that serve as annotations or explanations to make the code more understandable for yourself and others.
Knowing how to comment in Python is an important skill that can increase teamwork, maintenance, and comprehension of your codebase, regardless of your experience level with the language or whether you’re an experienced developer trying to make your code more readable.
In this detailed tutorial, we’ll explore the importance of commenting in Python code. We will discuss the types of Python comments, the proper syntax, and some best practices for adding comments to Python applications.
Let’s start with a look at the “why” of adding comments to Python codebases.
Table Of Contents
- The Importance of Comments in Python
- The Benefits of Adding Python Comments
- The Python Syntax for Comments
- The Best Practices for Python Comments
- Conclusion
- FAQs
The Importance of Comments in Python
Comments are fundamental building blocks of well-written Python code.
You cannot overestimate the significance of comments in Python code as they aid in enhancing maintainability, readability, and collaboration with your in-house and external teams, and other developers.
The Benefits of Adding Python Comments
Some of the key reasons why comments are essential in Python programming are:
Code Documentation
Comments act as documentation for your code. As such, they present background information, justifications for business logic(s), and explanations of the functions and goals of different codebase components.
Clarity and Readability
Well-placed comments enhance the readability of your code by providing additional information and clarifications. They make it easier for you and others to follow the logic and flow of the program, especially in complex or lengthy code.
Debugging and Troubleshooting
Comments are invaluable tools that act as markers or signposts during debugging. Well-written comments help you identify and isolate issues more efficiently. During code reviews, they provide hints, reminders, or explanations that aid in troubleshooting and resolving issues more efficiently.
Enhance Developer Skills
Comments serve as educational resources, especially in product and SaaS environments. By explaining programming concepts, algorithms, or techniques used in the code, they help beginners learn from existing codebases and understand best practices in Python programming.
Future Codebase Maintenance
Understanding the original author’s intent and design decisions is a crucial part of future maintenance.
When revisiting your code or collaborating with others to streamline maintenance, it is these comments that provide valuable insights like the reason behind specific code sections and guide you in making changes without inadvertently introducing errors.
The Python Syntax for Comments
You can only benefit from comments in Python when you adhere to the standard syntax for writing comments in Python.
Usually, this is a three-step process.
Indentation Alignment
Ensure that the indent level of your comment matches the code block it refers to. Thai provides a simple and quick way of associating the comments to the code block.
Use the Hash Symbol
Begin the comment with a hashtag (#) followed by a space. The hash character instructs the interpreter to ignore the input until the next newline character.
Write the Comment
Add the comment’s content, making sure that it occupies the current. The newline character terminates the comment, and Python will resume reading your code from the next line.
How to Write a Comment in Python
To add or mark a line as a comment, start a line with a hash symbol (#) followed by a space.
# this is an example of a comment
By using the hash sign (#), the code directs the Python interpreter to ignore the rest of the line. During the compilation, the interpreter acts like those lines don’t exist. However, you can still see it when you edit the source code file.
Types of Python Comments
Comments in Python are very versatile, and you can opt for several styles to convey your point across. We will now discuss the three types of Python comments.
Type #1: The Single-line Comments
This is the simplest and most common type of comment in Python apps. Single-line comments start with the hash character (#), followed by the comment text.
As mentioned previously, the Python interpreter considers anything following # on the same line a comment and ignores it during execution. These comments can appear anywhere in the code and are often used to add brief explanations or notes.
For instance,
# This is a single-line comment
x = 10 # Assigning the value 10 to variable x
Here,
- The first line is a single-line comment explaining the purpose of the code.
- The second line assigns the value 10 to the variable x, with an additional comment for clarification.
Type #2: The Multi-line Comments
Python code blocks consist of several lines of code grouped at the same indentation level.
Unlike other programming languages, Python does not have built-in support for multi-line comments. However, there are two effective ways to achieve multi-line commenting – consecutive single-line comments and multi-line strings (docstrings).
Consecutive Single-line Comments
In these comments, each line of the comment starts with a hash symbol (#).
This method is suitable for brief comments that span multiple lines. Consider the following example:
# This is
# a multi-line
# Comment using consecutive single-line comments
Multi-line Strings (Docstrings)
Comments enclosed within triple quotes (either three single quotes ”’ or three double quotes “””) are known as docstrings.
These are ideal for extensive documentation or comments for complex functions, classes, or modules. The following example illustrates this style of Python comments.
"""
This is a multi-line comment using
A multi-line string (docstring).
It can span multiple lines and is often used
For function, class, or module documentation.
"""
Type #3: Inline Comments in Python
An inline comment allows you to leave comments or notes on the same line as your code. This is useful when describing a series of complex operations.
To add an inline comment, go to the line where you wish to add the comment. Begin your inline comment with a hash symbol followed by a space. Write explanatory text after the space.
Consider this example:
# This is a comment print("This line is executed")
# This is also a comment # print("This line is commented out")
print("This line is also executed")
This is also a comment # print("This line is commented out")
print("This line is also executed")
In this example:
- The first and second lines are comments. They start with a hash (#), so the interpreter does not execute them.
- The third line is a print statement that will be executed.
- The fourth line is a commented-out print statement. It will not be executed as the hash character precedes it.
- The fifth line is another print statement that will be executed.
By commenting out code, you can temporarily disable it without deleting it, which is a very useful idea when you are debugging, testing alternative implementations, or temporarily needing to remove code blocks during development.
The Best Practices for Python Comments
Now that you know how to write Python comments, it is a good idea to know the best practices connected to the idea.
Be Clear and Concise
Write comments that are clear, concise, and easy to understand. Avoid ambiguity and use plain language to explain the code’s purpose, functionality, or rationale.
Be More Descriptive Than You Think You Need To Be
Use descriptive variables, functions, and class names to reduce the need for excessive comments. Well-chosen names can make the code self-explanatory and reduce the need for additional comments.
Comment as You Write
Incorporate commenting into your coding process by writing comments as you write code. This ensures that comments stay relevant and up-to-date with the codebase and helps you articulate your thought process.
Document Code Functionality
Use comments to document the functionality, behavior, and expected inputs/outputs of functions, methods, and classes.
Explain Complex Logic
Use comments to clarify complex computations, methods, or decision-making reasoning. Break down complex operations into smaller, understandable steps with explanations.
Avoid Over-commenting
Although comments are important, limit the number of comments, ensuring each one is insightful. Use comments to clarify intent, document edge cases, or highlight important details rather than restating obvious code.
Update Comments Regularly
As the code changes, constantly review and update the comments to ensure they are still valid and pertinent. Confusing or deceptive remarks can cause misunderstandings and mistakes.
Use Docstrings for Documentation
Docstrings (multi-line string literals enclosed in triple quotes) to provide documentation for functions, classes, and modules. Docstrings serve as comments and documentation and can be accessed using Python’s built-in help() function.
Also Read: Add Elements to Python Array: 3 Methods Inside!
Conclusion
Comments in Python are invaluable tools for enhancing code readability, facilitating collaboration, and providing documentation. By incorporating clear and concise comments into Python codebases, developers can improve code comprehension, streamline debugging, and ensure the maintainability of their projects. Remember to use comments judiciously, keeping them up-to-date and relevant to the code they accompany.
With effective commenting practices, Python developers can create codebases that are not only functional but also understandable and accessible to others. This can include improved software development across various domains, including server-side development.
At RedSwitches, we’re dedicated to helping you discover the perfect server solutions to drive your business to new heights. So, if you’re looking for a robust server for your Python applications, we offer the best-dedicated server pricing and deliver instant dedicated servers, usually on the same day the order gets approved.
FAQs
Q. How can syntax errors be avoided when writing comments in Python, especially when spanning separate lines?
Syntax errors in Python comments can be prevented by ensuring that comments are properly formatted and adhere to Python syntax rules. When spanning separate lines, comments should be indented consistently and correctly to maintain code readability and avoid syntax errors.
Q. What are Docstring comments, and how do they differ from other types of comments in Python?
Docstring comments are special comments in Python that provide documentation for functions, modules, classes, and methods. Unlike regular comments, docstrings are enclosed within triple quotes and are typically placed immediately after the function or class definition.
Q. What practices contribute to effective comments in Python code?
Effective comments in Python are clear, concise, and relevant to the code they accompany. They provide valuable insights, explanations, or documentation that enhance code readability and understanding. Additionally, comments should be kept up-to-date to ensure their accuracy and relevance.
Q. How should developers handle outdated comments in Python code to maintain code quality?
Developers should periodically review and update comments in Python code to reflect any changes to the codebase. Outdated comments can lead to confusion or misinformation, so ensuring they remain accurate and relevant to the code is essential.
Q. What are the differences between multi-line and single-line docstring comments in Python?
Multi-line docstring comments in Python provide comprehensive documentation for functions, modules, or classes and can span multiple lines. In contrast, single-line docstring comments are concise summaries typically used for brief documentation of functions or methods.
Q. How should developers balance code with comments to maintain code readability and understandability?
Developers should balance code and comments to ensure both contribute to code readability and understandability. Comments should provide helpful explanations or context without overwhelming the code, allowing developers to comprehend the code’s functionality.
