Comments are lines of text that are ignored by the Python interpreter. They are used to add notes to code or to temporarily disable a piece of code for testing purposes.

single line comments

Single-line comments start with the # character and continue until the end of the line. When the Python interpreter encounters a # character, it ignores the rest of the line, treating it as a comment.

#This line is a comment it will be ignored
print('Hello, World!') # This statement prints Hello, World! to the console
def add(a, b):
   #this function prints the sum of a and b
   result = a + b

add(50, 60)

In the following snippet we use a single line comment to stop a statement from being executed

#print('Hello, World!')
print('Goodbye, World!')

multi-line comments, and documentation strings

Although Python does not have a specific syntax for multi-line comments like some other programming languages, you can use triple quotes to create multi-line strings that are not assigned to any variable or used as docstrings.

This is a multi-line comment.
It can span across multiple lines.
These lines are not executed by the interpreter.

Using triple quotes to stop statements from being executed:

def add(a, b):
   print(a + b)

print('Function add was commented.')

Why use comments?

  1. Code Explanation: Comments provide a way to explain the functionality, logic, or intention of your code. They help other developers (including yourself) understand the purpose and implementation of specific code segments. Clear and concise comments can make your code more readable and maintainable.

  2. Documentation: Comments can serve as a form of documentation for your code. They provide high-level descriptions of how different parts of the code work, what functions or classes do, and any important considerations or limitations. Documentation comments can be valuable for future reference or when sharing code with others.

  3. Code Review and Collaboration: Comments aid in the code review process. They allow reviewers to provide feedback, ask questions, or suggest improvements directly in the code. Comments can facilitate collaboration among team members working on the same codebase.

  4. Debugging and Troubleshooting: Comments can be used to temporarily disable or "comment out" lines of code during debugging or troubleshooting. This allows you to isolate problematic code segments without deleting them, making it easier to identify and fix issues.

  5. Future Modifications: Comments can provide hints or suggestions for future modifications or enhancements to the code. They can outline potential improvements or alternative approaches, making it easier to revisit and update the code later.

It's worth noting that while comments are valuable, it's essential to maintain a balance. Over-commenting or including unnecessary comments can clutter the code and make it harder to read. Comments should be clear, concise, and relevant to the code they accompany.

By using comments effectively, you can improve code readability, maintainability, collaboration, and the overall quality of your software projects.