Comments can be used to explain Python code.

Comments can be used to make the code more readable.

Comments can be used to prevent execution when testing code.

Creating a Comment

Comments starts with a #, and Python will ignore them:

#This is a comment
print("Hello, World!")
Output
Hello, World!

Comments can be placed at the end of a line, and Python will ignore the rest of the line:

print("Hello, World!") #This is a comment
output
Hello, World!

Comments does not have to be text to explain the code, it can also be used to prevent Python from executing code:

#print("Hello, World!")
print("Cheers, Mate!")
Output
Cheers, Mate!

Multi Line Comments

Python does not really have a syntax for multi line comments.

To add a multiline comment you could insert a # for each line:

#This is a comment
#written in
#more than just one line
print("Hello, World!")
Output
Hello, World!

Or, not quite as intended, you can use a multiline string.

Since Python will ignore string literals that are not assigned to a variable, you can add a multiline string (triple quotes) in your code, and place your comment inside it:

"""
This is a comment
written in
more than just one line
"""
print("Hello, World!")
Output
Hello, World!

As long as the string is not assigned to a variable, Python will read the code, but then ignore it, and you have made a multiline comment.