Create knx.py (#7356)

* Create knx.py

light device for the knx component

* Fix doc strings

homeassistant/components/light/knx.py

@@ -0,0 +1,53 @@
+"""
+Support KNX Lighting actuators.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/Light.knx/
+"""
+import voluptuous as vol
+
+from homeassistant.components.knx import (KNXConfig, KNXGroupAddress)
+from homeassistant.components.light import (Light, PLATFORM_SCHEMA)
+from homeassistant.const import CONF_NAME
+import homeassistant.helpers.config_validation as cv
+
+CONF_ADDRESS = 'address'
+CONF_STATE_ADDRESS = 'state_address'
+
+DEFAULT_NAME = 'KNX Light'
+DEPENDENCIES = ['knx']
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Required(CONF_ADDRESS): cv.string,
+    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
+    vol.Optional(CONF_STATE_ADDRESS): cv.string,
+})
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Setup the KNX light platform."""
+    add_devices([KNXLight(hass, KNXConfig(config))])
+
+
+class KNXLight(KNXGroupAddress, Light):
+    """Representation of a KNX Light device."""
+
+    def turn_on(self, **kwargs):
+        """Turn the switch on.
+
+        This sends a value 1 to the group address of the device
+        """
+        self.group_write(1)
+        self._state = [1]
+        if not self.should_poll:
+            self.schedule_update_ha_state()
+
+    def turn_off(self, **kwargs):
+        """Turn the switch off.
+
+        This sends a value 1 to the group address of the device
+        """
+        self.group_write(0)
+        self._state = [0]
+        if not self.should_poll:
+            self.schedule_update_ha_state()