> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fly.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Setting up a Python Environment

## Initial Local Setup

Make sure that [Python](https://www.python.org/) is already installed on your computer along with a way to create virtual environments.

This allows you to run your project locally, and test that it works, before deploying it to Fly.io.

<Info>
  We recommend the latest [supported versions](https://devguide.python.org/versions/#supported-versions) of Python.
</Info>

## Dependency Management

For project and dependency management we use [Poetry](https://python-poetry.org/). Like most package managers, Poetry combines multiple tools in one.

You have other options:

* [uv](https://docs.astral.sh/uv/)
* [venv](https://docs.python.org/3/library/venv.html) and [pip](https://pip.pypa.io/)
* [Pipenv](https://github.com/pypa/pipenv)
* [pyenv](https://github.com/pyenv/pyenv)
* [pip-tools](https://pypi.org/project/pip-tools/)

If you are just starting out, it is easiest to follow along using `poetry`.
After installing it, you will have to set 2 flags for virtual environment management.

```bash theme={null}
poetry config virtualenvs.create true
poetry config virtualenvs.in-project true
```

This will make your development environment resemble what ends up happening inside the Docker image.

You can create a new project using this command:

```bash theme={null}
poetry new <app-name>
```

Once inside the project, you can add packages with the add command:

```bash theme={null}
poetry add <dep>
```

This will automatically create a virtual environment for you.

To interact with your virtual environment, you can prefix your commands with `poetry run`:

```bash theme={null}
poetry run python main.py
```

Alternatively, you can activate the environment:

```bash theme={null}
poetry env activate
```

This prints the activation command for your shell. To activate in one step:

```bash theme={null}
source $(poetry env activate)
python main.py
```

<Info>
  If you're using Poetry 2.0+ (the default when installed via `pipx`), the `poetry shell` command is no longer built in. Use `poetry run` (recommended) or `poetry env activate` as shown above. If you prefer `poetry shell`, you can install it as a plugin: `poetry self add poetry-plugin-shell`.
</Info>