Using comments in Python 3

By Lenin Mishra

A lot of times you will have difficulties figuring out what is going on in a Python program. Even if you are the author of the program, you might have difficulties navigating your own code after a period of time.

Comments are very useful in such scenarios as they describe the intent and functionality of your code.

In Python, you can write comments in 3 different ways.

  1. Single line comments
  2. Multi-line Comments
  3. Docstrings

Single line Comments

You can use the hash symbol # to write single-line comments in Python. Everything that comes after the hash symbol # is ignored by the Python interpreter.


# printing Hello World
print("Hello World!")

x = 10
y = 20
# Tuple Swap
x, y = y, x

str1 = "Pylenin loves Python"
# Return the first and last character
print(str1[0] + str1[-1])

Multi-line Comments

Python doesn’t provide any unique way for multi-line comments. However, any string can be used as a comment in Python, as long as it is not asigned to a variable. Python interpreter ignores such strings.


"This line will be ignored"
print("Pylenin loves Python")

Bigger comments can be written
over multiple lines.
This is a multi-line comment.
print("Pylenin loves Python")

Run the above code and you will see that no errors are raised by Python.


Docstrings are not similar to comments. However, they have a similar purpose.

Docstring is short for documentation string.

Python docstrings are the string literals that appear right after the definition of a function, method, class, or module. They are used to provide a meaningful description about the above mentioned objects.

Use triple quotes to write docstrings.


def addition(x,y):
    """Takes x and y and returns their sum"""
    return x+y



Takes x and y and returns their sum

You can also use Docstrings in a Python class.


class Person:
    """Stores the name, age and country of a person"""
    def __init__(self, name, age, country): = name
        self.age = age = country



Stores the name, age and country of a person

Where to use comments and Docstrings?

Use comments where you believe the way your code written is not too obvious to understand for a programmer.

Use docstrings to provide information about various objects like functions and classes in your code.