home-assistant.io/source/_components/python_script.markdown

layout, title, description, date, sidebar, comments, sharing, footer, logo, ha_category, ha_release, ha_qa_scale

layout	title	description	date	sidebar	comments	sharing	footer	logo	ha_category	ha_release	ha_qa_scale
page	Python Scripts	Instructions on how to setup Python scripts within Home Assistant.	2017-06-15 19:59	true	false	true	true	home-assistant.png	Automation	0.47	internal

This component 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
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

{% linkable_title 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:

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

{
  "name": "you"
}

{% linkable_title 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.

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.

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

For more examples, visit the Scripts section in our forum.