Python Comments Tutorial

 Python Comments are notes in your code that are not executed by the Python interpreter. They are meant to help you (and others) understand what the code is doing. Comments can be single-line or multi-line.

Why Do Comments Matter?

1. Clarity: Comments help clarify the purpose of the code for anyone reading it, including your future self.
2. Documentation: They serve as documentation to explain complex sections of code, making it easier for others to follow along.
3. Debugging: Comments can also help you disable parts of your code for testing without deleting it.

Types of Comments

Single-Line Comments

 
Single-line comments start with a # and continue until the end of that line. And in output we can note that there is no effect of adding comments.

Example:

# This is a single-line comment  
print("Hello, World!")  # This prints a greeting  

 
Output:

Hello, World!  

Multi-Line Comments

 
Multi-line comments are enclosed within triple quotes (''' or """). They can span multiple lines and are often used for longer explanations.

Example:

"""  
This is a multi-line comment.  
It can span multiple lines.  
"""  
print("This code is still working!")  # This prints another greeting  

 
Output:

This code is still working!  

How Comments Help

 
Let’s see how comments can improve code understandability. First, we’ll look at a piece of code without comments, then with comments.

Example Without Comments

To understand a_n what is doing we need to go through full code.

def a_n(a, b):  
    return a + b  
  
result = add_numbers(5, 3)  
print(result)  

Output:

8  

 
In the code above, it’s not immediately clear what the function does just by looking at it. Someone reading this might need to dive deeper to understand the purpose of a_n.

Example With Comments

# This function adds two numbers  
def a_n(a, b):  
    return a + b  # Return the sum of a and b  
  
result = a_n(5, 3)  # Call the function with arguments 5 and 3  
print(result)  # Print the result  

Output:

8  

 
In this second example, the comments make it clear what the code is doing. Anyone reading this code, even after a long time, will easily understand its purpose.

Best Practices for Comments

1. Be Clear and Concise: Write comments that are easy to understand and directly related to the code.
2. Avoid Obvious Comments: Don’t explain what simple code is doing unnecessarily. For example, writing # This adds two numbers next to a line of code that is clearly doing so is redundant.
3. Update Comments: Make sure to update comments if you change the related code to keep them accurate.

Practice Tasks

Task 1: Add Comments

1. Write a simple function that multiplies two numbers.
2. Add comments explaining what each part of the function does.

Task 2: Comment Out Code

1. Create a loop that prints numbers from 1 to 5.
2. Write a comment explaining the purpose of the loop, then comment out the print statement temporarily to see how the code behaves without it.

Guidance

 
Take it slow and think about what each part of your code does as you write your comments. The more clear you are, the easier it will be for others (and your future self) to understand your work.

Motivation

 
Try the tasks and share your answers in the comments to get appreciated! Happy commenting!