From 55aa341daba2bac150e8e4924c5b5c8fdd94c4e5 Mon Sep 17 00:00:00 2001
From: Arjan van Balken <vanbalken@users.noreply.github.com>
Date: Sun, 2 Feb 2020 15:45:05 +0100
Subject: [PATCH] Add unique_id to essent sensors (#31408)

* Fix mix-up of sensor entities and their values

* Prevent multiple calls for the same meter
---
 homeassistant/components/essent/sensor.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/homeassistant/components/essent/sensor.py b/homeassistant/components/essent/sensor.py
index b106d9d2ae66..e3ce1ccaafa5 100644
--- a/homeassistant/components/essent/sensor.py
+++ b/homeassistant/components/essent/sensor.py
@@ -1,5 +1,6 @@
 """Support for Essent API."""
 from datetime import timedelta
+from typing import Optional
 
 from pyessent import PyEssent
 import voluptuous as vol
@@ -73,7 +74,7 @@ class EssentBase:
     def update(self):
         """Retrieve the latest meter data from Essent."""
         essent = PyEssent(self._username, self._password)
-        eans = essent.get_EANs()
+        eans = set(essent.get_EANs())
         for possible_meter in eans:
             meter_data = essent.read_meter(possible_meter, only_last_meter_reading=True)
             if meter_data:
@@ -92,6 +93,11 @@ class EssentMeter(Entity):
         self._tariff = tariff
         self._unit = unit
 
+    @property
+    def unique_id(self) -> Optional[str]:
+        """Return a unique ID."""
+        return f"{self._meter}-{self._type}-{self._tariff}"
+
     @property
     def name(self):
         """Return the name of the sensor."""