How to Write Comments in Python (Single-line, Multi-line, Shortcuts & Indentation Tips)

Hello, this is BlockDMask.

Today, we’re going to learn how to write comments in Python.
Python supports both single-line and multi-line comments. You can freely use them depending on the situation.

Did you know that some Python comments require proper indentation?
I once struggled with PyCharm due to indentation issues in comments, so I’m writing this post to help you avoid the same mistake.

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1. Types of Comments in Python

▶ Single-line Comment: #

Single-line comments start with the # symbol.

Example 1 - Comment on an empty line

# This is a single-line comment example 1
def comment_example():
    print("Comment example. DMask")

Typically, one space is added after the # symbol before writing the comment.

Example 2 - Comment at the end of a line

def comment_example():
    print("Comment example. Mask")  # This is single-line comment example 2

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▶ Multi-line Comment: Triple Quotes """ or '''

Multi-line comments can be written in two ways:

1) Triple double quotes """ ... """

def comment_example():
    print("Comment example. Block")

"""
This is a multi-line comment.
You can freely write explanations here.
Finish by closing with triple double quotes.
"""
a = 3  # regular code 1
b = 4  # regular code 2

2) Triple single quotes ''' ... '''

while True:
    '''
    This program performs certain operations.
    Please mention the source when sharing.
    Additional explanations go here.
    '''
    print("=" * 30)

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2. Comment Shortcuts (PyCharm, IDLE, VSCode, etc.)

Using shortcuts makes it easy to add or remove comments. Most editors use similar shortcut keys.

▶ Common shortcuts for PyCharm, VSCode, and most IDEs

• Windows: CTRL + /
• Mac OS: Command + /

▶ Python IDLE shortcuts

• Add comment: ALT + 3
• Remove comment: ALT + 4

▶ Multi-line comment example using shortcut

Select multiple lines and apply the shortcut to comment or uncomment them.

Original Code:

def add_numbers(a, b):
    print(f"{a} + {b} = {a + b}")

x = 10
y = 20
add_numbers(x, y)

After Applying Shortcut:

# def add_numbers(a, b):
#     print(f"{a} + {b} = {a + b}")
# 
# x = 10
# y = 20
# add_numbers(x, y)

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3. Important: Indentation in Python Comments

Unlike languages like C, C++, or C#, Python is sensitive to indentation — even for comments.

▶ Indentation error example

class CommentExample:
'''
Python comments must be properly indented. This will cause an error.
'''
    def __init__(self):
        a = 10
        b = 20

Error: IndentationError: expected an indented block

▶ Correct indentation example

class CommentExample:
    '''
    Python comments must be properly indented.
    '''
    def __init__(self):
        a = 10
        b = 20

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That’s it for today’s post about Python comments.
Thank you for reading!