Comments in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What symbol is used to start a single-line comment in Python?

The # symbol is used to start a single-line comment in Python. Anything after # on that line is ignored by the Python interpreter.

beginner

How do you write a multi-line comment in Python?

Python does not have a special multi-line comment syntax. Instead, you can use multiple single-line comments starting with # or use a multi-line string with triple quotes (''' or """) which is ignored if not assigned to a variable or used as a docstring.

beginner

Why are comments important in Python code?

Comments help explain what the code does in simple words. They make the code easier to understand for others and for yourself when you come back later.

beginner

Can comments affect how a Python program runs?

No, comments do not affect the program's behavior. The Python interpreter ignores comments completely when running the code.

beginner

Example: What will this code output?<br>

print('Hello')  # This prints Hello

The output will be:<br>

Hello

<br>The comment after # is ignored and does not affect the output.

Which symbol starts a comment in Python?

A /*

B //

C #

D <!--

In Python, the # symbol starts a comment. Other symbols are used in different languages.

What happens to comments when Python runs the code?

A They are ignored

B They are executed as code

C They cause errors

D They print on the screen

Comments are ignored by Python and do not affect the program.

How can you write a multi-line comment in Python?

A Use multiple lines starting with #

B Use /* and */

C Use <!-- and -->

D Use // on each line

Python uses multiple single-line comments starting with # for multi-line comments.

Which of these is NOT a reason to use comments?

A Explain code to others

B Make code run faster

C Make code easier to understand

D Help yourself remember code purpose

Comments do not affect speed; they only help with understanding.

What will this code print?<br>print('Hi') # This is a greeting

A Hi # This is a greeting

B Error

C This is a greeting

D Hi

The comment after # is ignored, so only 'Hi' is printed.

Explain how to write comments in Python and why they are useful.

Think about how you would explain your code to a friend.

Describe the difference between comments and code in Python.

Focus on what Python does with comments versus code.