Setup: Run Your First Python Program

This page helps you install Python, create one file, and see your first successful output. Complete the quick start before learning about virtual environments.

Before installing anything

If you use a school or office computer, ask a parent, teacher, or administrator before installing software. Do not remove a Python installation that already belongs to the operating system.

You need:

  • a computer running Windows, macOS, or Linux;
  • permission to install software;
  • a text editor;
  • a terminal, which is a window where you type commands.

Choose only the section for your operating system.

Windows quick start

Step 1 — install Python

Use the official Python Install Manager instructions. It can be installed from Python.org or the Microsoft Store.

After installation, open PowerShell from the Start menu and type:

python --version

If your installation uses the py command, this also works:

py --version

You should see a Python 3 version. The exact numbers may be newer than examples in this course.

Step 2 — create a learning folder 

mkdir python-learning
cd python-learning
  • mkdir creates a folder.
  • cd moves the terminal into that folder.

Step 3 — create and run hello.py

Open the python-learning folder in your editor. Create a file named hello.py and type:

print("Hello, Python!")

Save the file. Return to PowerShell and run:

python hello.py

If python does not work but py does, run:

py hello.py

Expected output:

Hello, Python!

macOS quick start

Step 1 — install Python

Download the current supported Python 3 installer from Python Releases for macOS. Use the normal .pkg installer and complete its instructions.

Open Terminal and type:

python3 --version

You should see a Python 3 version. Do not delete or modify Python supplied by macOS or Apple development tools.

Step 2 — create a learning folder 

mkdir python-learning
cd python-learning

Step 3 — create and run hello.py

Open the python-learning folder in your editor. Create hello.py:

print("Hello, Python!")

Save it and run:

python3 hello.py

Expected output:

Hello, Python!

Linux quick start

Python 3 is already available on many Linux distributions. First try:

python3 --version

If Python is unavailable on Debian or Ubuntu, use:

sudo apt update
sudo apt install python3 python3-venv python3-pip

For Fedora, Arch, or another distribution, use its package manager and the official Python Unix guide.

Create the learning folder:

mkdir python-learning
cd python-learning

Create hello.py in your editor:

print("Hello, Python!")

Save it and run:

python3 hello.py

What just happened? 

hello.py -> Python reads the file -> print() displays text -> terminal shows output
  • hello.py is a Python source file.
  • .py is the usual filename ending for Python code.
  • python, py, or python3 starts the Python interpreter.
  • An interpreter is the program that reads and runs Python instructions.

If you saw Hello, Python!, pause and enjoy that small win. Your computer has successfully run your code.

A virtual environment is a private project box for Python tools and installed packages. One project’s packages will not interfere with another project’s packages.

computer Python
├── project A .venv -> project A packages
└── project B .venv -> project B packages

The Basic examples use the standard library and can run without extra packages. Creating .venv now is still a useful habit.

macOS and Linux

From inside python-learning:

python3 -m venv .venv
source .venv/bin/activate
python --version

Windows PowerShell

From inside python-learning:

python -m venv .venv
.venv\Scripts\Activate.ps1
python --version

If you normally use py, create it with:

py -m venv .venv

When activation succeeds, the terminal prompt normally begins with (.venv). Activation makes the plain python command select the environment’s interpreter.

To leave the environment later:

deactivate

If PowerShell blocks activation, do not randomly weaken computer security. You may run the environment directly:

.venv\Scripts\python.exe hello.py

Choose an editor

Read Editor Setup. Any editor that saves plain .py files is acceptable. IDLE, which is included with many Python installations, is enough for this course.

Learn six terminal commands

Read Terminal Basics. You only need a few commands to move between folders and run files.

Setup checkpoint

  • A Python 3 version command works.
  • The python-learning folder exists.
  • hello.py contains the one-line program.
  • Running the file displays Hello, Python!.
  • I know which command works on my computer: python, py, or python3.
  • I either created .venv or understand that I can return to that optional step.

If a checkpoint fails, open Setup Troubleshooting.

Table of contents