---
title: "Python Scripts"
description: "Instructions on how to setup Python scripts within Home Assistant."
logo: home-assistant.png
ha_category:
  - Automation
ha_release: 0.47
ha_qa_scale: internal
---

This integration allows you to write Python scripts that are exposed as services in Home Assistant. Each Python file created in the `<config>/python_scripts/` folder will be exposed as a service. The content is not cached so you can easily develop: edit file, save changes, call service. The scripts are run in a sandboxed environment. The following variables are available in the sandbox:

| Name | Description |
| ---- | ----------- |
| `hass` | The Home Assistant object. Access is only allowed to call services, set/remove states and fire events. [API reference][hass-api]
| `data` | The data passed to the Python Script service call.
| `logger` | A logger to allow you to log messages: `logger.info()`, `logger.warning()`, `logger.error()`. [API reference][logger-api]

[hass-api]: /developers/development_hass_object/
[logger-api]: https://docs.python.org/3.4/library/logging.html#logger-objects

## Writing your first script

 - Add to `configuration.yaml`: `python_script:`
 - Create folder `<config>/python_scripts`
 - Create a file `hello_world.py` in the folder and give it this content:

```python
name = data.get('name', 'world')
logger.info("Hello {}".format(name))
hass.bus.fire(name, { "wow": "from a Python script!" })
```

 - Start Home Assistant
 - Call service `python_script.hello_world` with parameters

```json
{
  "name": "you"
}
```

## Calling Services

The following example shows how to call a service from `python_script`. This script takes two parameters: `entity_id` (required), `rgb_color` (optional) and calls `light.turn_on` service by setting the brightness value to `255`.

```python
# turn_on_light.py
entity_id = data.get('entity_id')
rgb_color = data.get('rgb_color', [255, 255, 255])
if entity_id is not None:
    service_data = {'entity_id': entity_id, 'rgb_color': rgb_color, 'brightness': 255 }
    hass.services.call('light', 'turn_on', service_data, False)
```
The above `python_script` can be called using the following JSON as an input.

```json
{"entity_id": "light.bedroom", "rgb_color": [255, 0, 0] }
```

## Documenting your Python scripts

You can add descriptions for your Python scripts that will be shown in the Call Services tab of the Developer Options page. To do so, simply create a `services.yaml` file in your `<config>/python_scripts` folder. Using the above Python script as an example, the `services.yaml` file would look like:

```yaml
# services.yaml
turn_on_light:
  description: Turn on a light and set its color. 
  fields:
    entity_id:
      description: The light that will be turned on.
      example: light.bedroom
    rgb_color:
      description: The color to which the light will be set.
      example: [255, 0, 0]
```

For more examples, visit the [Scripts section](https://community.home-assistant.io/c/projects/scripts) in our forum.