Python Basics
Python Comments
Comments are lines in your code that Python ignores when running the program. They exist purely to help humans understand what the code does.
Single-Line Comments
In Python, anything after a hash symbol (#) on a line is treated as a comment and is not executed. You can put a comment on its own line or after a statement.
# This program greets the user
name = "Karan" # storing the user's name
print(name)Multi-Line Comments
Python does not have a dedicated multi-line comment symbol. The common workaround is to start each line with #, or to use a multi-line string (triple quotes) that is not assigned to anything, which Python simply ignores as an expression.
# This function calculates the total price
# including tax and discount
# Author: Learning Python Team
"""
This is technically a string, but since it
is not assigned to a variable, Python
treats it like a multi-line comment.
"""Docstrings
A docstring is a special string written as the first statement inside a function, class or module to describe what it does. Docstrings use triple quotes and, unlike regular comments, can be accessed using the built-in help() function.
def add_numbers(a, b):
"""Return the sum of two numbers."""
return a + b
print(add_numbers(4, 5))Why Comments Matter
- They explain why code does something, not just what it does
- They help teammates (and future you) understand the logic faster
- They make debugging and code reviews much easier
- Well-documented code is expected in real internship and job projects
Write comments that explain intent and reasoning, not obvious things — the code itself already shows what a simple line does.