Bump minimum python to 3.6 to use f string

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.5, 3.8, 3.9]
+        python-version: [3.6, 3.8, 3.9]
 
     steps:
       - uses: actions/checkout@v2

README.rst

@@ -27,7 +27,7 @@ run those other applications.
 Requirements
 ------------
 
--  Python 3.5 or newer with asyncio
+-  Python 3.6 or newer with asyncio
 -  An Anthem MRX or AVM receiver or processor
 
 Known Issues

anthemav/protocol.py

@@ -170,7 +170,7 @@ def __init__(self, update_callback=None, loop=None, connection_lost_callback=Non
         self.transport = None
 
         for key in LOOKUP:
-            setattr(self, "_" + key, "")
+            setattr(self, f"_{key}", "")
 
         self._Z1POW = "0"
 
@@ -269,7 +269,7 @@ def _assemble_buffer(self):
 
         for message in self.buffer.split(";"):
             if message != "":
-                self.log.debug("assembled message " + message)
+                self.log.debug("assembled message %s", message)
                 self._parse_message(message)
 
         self.buffer = ""
@@ -285,7 +285,7 @@ def _populate_inputs(self, total):
         """
         total = total + 1
         for input_number in range(1, total):
-            self.query("ISN" + str(input_number).zfill(2))
+            self.query(f"ISN{input_number:02d}")
 
     def _parse_message(self, data):
         """Interpret each message datagram from device and do the needful.

tests/test_protocol.py

@@ -1,6 +1,4 @@
-from typing import Protocol
 from anthemav.protocol import ALM_NUMBER, LOOKUP
-import pytest
 from anthemav import AVR
 from unittest.mock import patch
 
@@ -44,3 +42,11 @@ def test_mute_force_refresh():
     with patch.object(avr, "query") as mock:
         avr.mute = True
         mock.assert_called_once_with("Z1MUT")
+
+
+def test_populate_input():
+    avr = AVR()
+    with patch.object(avr, "query") as mock:
+        avr._populate_inputs(2)
+        mock.assert_any_call("ISN01")
+        mock.assert_called_with("ISN02")