# Setup PDM for GitHub Action

A GitHub Action that installs pdm properly for all Python versions

## Why do I need this action?

As you know, PDM requires Python 3.7 and higher to install the package, while till now(March 2021) Python 3.6 is still widely used by many libraries. The version requirement will prevent potential users from adopting PDM. However, it is a misunderstanding, PDM CAN run projects using Python 3.6 or even Python 2!
But it is still not obvious and it is a pain for developers to properly build their CI workflows. So I made `pdm-project/setup-pdm` to solve the problem. It is PDM-for-CI done right!

## Usage

Include the action in your workflow yaml:

```yaml
steps:
  - uses: actions/checkout@v3
  - name: Setup PDM
    uses: pdm-project/setup-pdm@v4
    # You are now able to use PDM in your workflow
  - name: Install dependencies
    run: pdm install
```

You don't need `actions/setup-python` actually.

## Action Inputs

This action supports the following inputs:

| Input                      | Default               | Description                                                                                                                          |
| -------------------------- | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| `python-version`           | Not specified         | Version range or exact version of a Python version to use, using SemVer's version range syntax.                                      |
| `python-version-file`      | `pyproject.toml`      | File containing the Python version to use. Example: .`python-version`                                                                |
| `architecture`             | `x64`                 | The target architecture (x86, x64) of the Python interpreter.                                                                        |
| `allow-python-prereleases` | `false`               | Allow prerelease versions of Python to be installed.                                                                                 |
| `token`                    | `${{ github.token }}` | Used to pull python distributions from actions/python-versions. Since there's a default, this is typically not supplied by the user. |
| `version`                  | Not specified         | The version of PDM to install, or 'head' to install from the main branch.                                                            |
| `prerelease`               | `false`               | Allow prerelease versions of PDM to be installed                                                                                     |
| `enable-pep582`            | `false`               | Enable PEP 582 package loading globally.                                                                                             |
| `cache`                    | `false`               | Cache PDM installation.                                                                                                              |
| `cache-dependency-path`    | `pdm.lock`            | The dependency file(s) to cache.                                                                                                     |
| `update-python`            | `true`                | Whether to update the environment with the requested Python                                                                          |

## Action Outputs

This action also exposes the following outputs:

| Output           | Description                                                                       |
| ---------------- | --------------------------------------------------------------------------------- |
| `python-version` | The installed Python or PyPy version. Useful when given a version range as input. |
| `python-path`    | The absolute path to the Python or PyPy executable.                               |
| `pdm-version`    | The installed PDM version.                                                        |
| `pdm-bin`        | The absolute path to the PDM executable.                                          |

## Caches

This action has a built-in cache support. You can use it like this:

```yaml
- uses: pdm-project/setup-pdm@v3
  with:
    python-version: 3.9
    cache: true
```

The default path to calculate the cache key is `./pdm.lock`, you can change it by setting the `cache-dependency-path` input.

**Using a list of file paths to cache dependencies**

```yaml
- uses: pdm-project/setup-pdm@v3
  with:
    python-version: 3.9
    cache: true
    cache-dependency-path: |
      ./pdm.lock
      ./pdm.new.lock
```

**Using a glob pattern to cache dependencies**

```yaml
- uses: pdm-project/setup-pdm@v3
  with:
    python-version: 3.9
    cache: true
    cache-dependency-path: '**/pdm.lock'
```