Python Comments

Dec 18, 2020

Comments are an integral part of programming.

There are three different ways to write Python comments, documentation strings (docstrings for short), inline comments, and block comments.

Block Comments

Step 1 : Block and inline comments start with a pound sign, #. A block comment comes in the line before the statement it annotates and is placed at the same indentation level:

# increment counter

counter = counter + 1

Inline Comments

Step 2 : Inline comments are placed on the same line as the statement it annotates:

print(foobar) # this will raise an error since foobar isn't defined

Documentation Strings

Step 3 : A documentation string, or docstring for short, is a literal string used as a Python comment. It is written and wrapped within triple quotation marks; """ or '''. Docstrings are often used to document modules, functions, and class definitions. The following is an example module that's been documented with a docstring. Module docstrings should be put at the beginning of the file:


This script can be called with two integer arguments to return their sum


import sys

num_1 = int(sys.argv[1])

num_2 = int(sys.argv[2])

print(num_1, "+", num_2, "=", num_1 + num_2)

Step 4 : you can also use docstrings to write multiline comments:


This loop goes through all the numbers from 1 to 100

printing each out


for i in range(1, 101):