Move imports to top for etherscan (#29426)

homeassistant/components/etherscan/sensor.py

@@ -1,6 +1,7 @@
 """Support for Etherscan sensors."""
 from datetime import timedelta
 
+from pyetherscan import get_balance
 import voluptuous as vol
 
 from homeassistant.components.sensor import PLATFORM_SCHEMA
@@ -75,7 +76,6 @@ class EtherscanSensor(Entity):
 
     def update(self):
         """Get the latest state of the sensor."""
-        from pyetherscan import get_balance
 
         if self._token_address:
             self._state = get_balance(self._address, self._token_address)