Avoid regex overhead in processing esphome bluetooth advertisements (#83246)

homeassistant/components/esphome/bluetooth/scanner.py

@@ -1,7 +1,6 @@
 """Bluetooth scanner for esphome."""
 from __future__ import annotations
 
-import re
 from typing import Any
 
 from aioesphomeapi import BluetoothLEAdvertisement
@@ -9,8 +8,6 @@ from aioesphomeapi import BluetoothLEAdvertisement
 from homeassistant.components.bluetooth import BaseHaRemoteScanner
 from homeassistant.core import callback
 
-TWO_CHAR = re.compile("..")
-
 
 class ESPHomeScanner(BaseHaRemoteScanner):
     """Scanner for esphome."""
@@ -18,9 +15,10 @@ class ESPHomeScanner(BaseHaRemoteScanner):
     @callback
     def async_on_advertisement(self, adv: BluetoothLEAdvertisement) -> None:
         """Call the registered callback."""
-        address = ":".join(TWO_CHAR.findall("%012X" % adv.address))  # must be upper
+        # The mac address is a uint64, but we need a string
+        mac_hex = f"{adv.address:012X}"
         self._async_on_advertisement(
-            address,
+            f"{mac_hex[0:2]}:{mac_hex[2:4]}:{mac_hex[4:6]}:{mac_hex[6:8]}:{mac_hex[8:10]}:{mac_hex[10:12]}",
             adv.rssi,
             adv.name,
             adv.service_uuids,