Installing Python and VS Code

What you're installing

You need two things.

The first is Python itself: the interpreterinterpreterThe program that reads your Python code and carries it out, line by line. that runs your code. The Python in this page is the same language, packed to run inside a browser. Press Run to ask it which version it is.

import sys
print("Python", sys.version_info.major, sys.version_info.minor)

That means Python 3.14. The first line borrows a built-in toolbox called sys that knows about the Python running your code; you'll learn about import later. On your computer, anything from 3.12 up is fine for this course.

The second is a code editorcode editorAn app for writing code. It colors your code, spots some mistakes, and runs programs with one click.. We'll use VS Code: it's free, runs on Windows, macOS, and Linux, and has an official Python extension from Microsoft.

You'll also use the terminalterminalA window where you type commands for your computer instead of clicking. Also called the command line, or PowerShell on Windows.. It looks old-fashioned, but it's the most direct way to talk to Python.

Installing Python

Pick your system. The steps are different on each one.

# Ubuntu, Debian, Linux Mint
sudo apt install python3
 
# Fedora
sudo dnf install python3

Checking that it worked

In your terminal, ask Python for its version. On Windows the command is python; on macOS and Linux it's python3.

python --version

python3 --version

python3 --version

You should see one line with a version number, for example:

Python 3.14.2

Your number may differ; 3.12 or higher is what matters. If you see that, Python is installed and your terminal can find it.

Notice that python --version is a command for the terminal, not Python code. The terminal and Python are two different places. Here's what happens if you give that same text to Python itself.

print("python --version")

python --version

And without the quotes, Python tries to understand it as code and fails. Run it and look at the last line.

python --version

Python says NameError: name 'python' is not defined. If you ever see this on your own computer, you typed a terminal command inside Python. Leave Python by typing exit() and pressing Enter, then run the command again in the plain terminal.

Setting up VS Code

1. Install VS Code

   Download it from code.visualstudio.com and install it with the default choices.

2. Add the Python extension

   Open VS Code, click the Extensions icon on the left (or press Ctrl + Shift + X, Cmd + Shift + X on a Mac), search for Python, and install the one published by Microsoft.

3. Open a folder for your code

   Make a folder called python-course anywhere you like. In VS Code, choose File, then Open Folder, and pick it. Every file you make in this course can live there.