Python comments are used to add notes, explanations, or annotations within the code that the interpreter does not execute. They help improve the readability of the code by explaining what certain parts of the program do. Comments can also be used to temporarily disable code or provide instructions for other developers working on the code.
Types of Comments in Python:
1. Single-line Comments
Single-line comments start with the # symbol. Everything after the # on that line is considered a comment and is ignored by the Python interpreter.
Example:
# This is a single-line comment
x = 20 # This comment is after a statement
2. Multi-line Comments
Python doesn’t have an official multi-line comment syntax like some other programming languages. However, multi-line comments can be achieved using triple quotes (''' or """). While these are technically string literals, if they aren’t assigned to a variable or used in code, Python ignores them, effectively treating them as comments.
'''
This is a multi-line comment.
It spans multiple lines.
'''
print("Hello, World!")
Alternatively, multiple single-line comments can be used for multi-line comments:
# This is a comment
# that spans multiple lines
# using single-line comments.
When to Use Comments:
1. Explain Complex Logic: Use comments to clarify complicated or non-obvious parts of the code.
# Check if the user input is a positive integer
if number > 0:
print("Positive number")
2. Provide Metadata: Comments can be used at the top of a script to describe metadata like the author’s name, date of creation, and purpose of the program.
# Author: John Taylor
# Date: 2023-07-05
# Description: This script performs basic operations.
3. Disable Code: Temporarily comment out code for debugging or testing purposes.
# print("This line is commented out and won't run.")
print("This line will run.")