Python Comments

Comments are non-executable statements written in a Python program to explain the code. Python ignores comments during program execution. Comments make programs easier to understand, read and maintain.

Why Use Comments?

• To explain the purpose of a section of code.
• To make the program easier to understand.
• To document important information about the program.
• To temporarily disable a line of code during testing.

Single-Line Comments

A single-line comment starts with the # symbol. Everything written after # on that line is treated as a comment.

# This is a comment
print("Hello Python")

Hello Python

Comment After a Statement

A comment can also be written on the same line after a Python statement.

x = 10       # Store 10 in x
print(x)     # Display the value

10

Comments in Multiple Lines

Python does not have a separate multi-line comment symbol. Multiple single-line comments can be written by using # on each line.

# Calculate the area of a circle
# radius is given by the user
# Formula: area = 3.14 * radius * radius

radius = 5
area = 3.14 * radius * radius
print(area)

78.5

Using Triple Quotes

Triple-quoted strings using ''' or """ can span multiple lines. They are mainly used for docstrings in Python. They should not be treated as the normal way of writing comments.

"""
This is a multi-line string.
It can contain several lines.
"""

print("Python")

Python

Comments in Functions

Comments can be used to describe what a function does.

def add(a, b):
    # Return the sum of two numbers
    return a + b

print(add(10, 20))

30

Commenting Out Code

A line can be temporarily disabled by placing # before it.

print("Start")

# print("This line will not execute")

print("End")

Start
End

Important Points

• Use # for a single-line comment.
• Python does not execute comments.
• Comments improve code readability.
• Comments can be written before or after a statement.
• Use meaningful comments that explain the code clearly.