# 2. Install Python

You do **not** need to install Python itself, and you should not install Anaconda
for this course. We use [pixi](https://pixi.sh), which reads the environment
description in the repository and installs the packages used in the course.

```{admonition} What is pixi?
Pixi is a tool for managing Python environments. It is similar to Conda or
virtualenv, but it is designed to be simpler and more reproducible. It reads a
description of the environment from a file and installs the packages in a
single command. It also provides a way to run commands inside the environment
without having to activate it first.
```


## 1. Open a terminal

**macOS**: open the Terminal app (in Applications → Utilities).

**Linux**: open a terminal (Ctrl+Alt+T).

**Windows**: open PowerShell (over the Start menu or press Win+R, type `powershell`, and press Enter).


## 2. Install pixi

**macOS / Linux**: in the terminal:

```bash
curl -fsSL https://pixi.sh/install.sh | sh
```

**Windows**: in PowerShell:

```powershell
powershell -ExecutionPolicy ByPass -c "irm -useb https://pixi.sh/install.ps1 | iex"
```

Then **close the terminal and open a new one**, so the change to your PATH takes
effect, and check that the following command works:

```bash
pixi --version
```

If you already had pixi installed from before, bring it up to date with
`pixi self-update`: the course needs a recent version.

## 3. Install git

```{admonition} What is git?
Git is a version control system. It is used to download the course material from
GitHub and to keep it up to date. You do not need to learn git for this course, but you will use it to download the course material and to update it.
```


Check whether you already have it with `git --version`.

If not, type the following command in the terminal, which can take a minute:

```bash
pixi global install git
```

Next: [set up the course Python environment](setup_environment.md).