Installing and Running Python

What You’ll Learn

You’ll learn how to download Python, verify the installation, and run basic Python code from the terminal.

Installation

To use Python on your computer, you need to download and install it from the official website.

1. Go to python.org/downloads.
2. Download the latest version for your operating system.
3. IMPORTANT (Windows): During installation, make sure to check the box that says “Add Python to PATH”.

Verifying Installation

Once installed, open your terminal or command prompt and type:

python --version
# or
python3 --version

Expected Output:

Python 3.12.0

Running Python Code

You can run Python code in two ways:

1. Interactive Mode (REPL)

Type python in your terminal to open the interactive shell. You can type Python commands directly and see immediate results.

>>> 5 + 5
10
>>> print("Hello")
Hello

2. Running a Script File

Create a file named script.py and add your code. Then, run it from the terminal:

python script.py

Common Mistakes

• Forgetting to check “Add to PATH”: If you get a “command not found” error when typing python, this is the most likely cause. You’ll need to reinstall and check the box, or add it to PATH manually.