diff --git a/custom_components/localtuya/__init__.py b/custom_components/localtuya/__init__.py
index eae9853..d4549a1 100644
--- a/custom_components/localtuya/__init__.py
+++ b/custom_components/localtuya/__init__.py
@@ -1,4 +1,4 @@
-"""The LocalTuya integration. """
+"""The LocalTuya integration."""
 import asyncio
 import logging
 import time
diff --git a/custom_components/localtuya/cloud_api.py b/custom_components/localtuya/cloud_api.py
index b55c46f..76687c2 100755
--- a/custom_components/localtuya/cloud_api.py
+++ b/custom_components/localtuya/cloud_api.py
@@ -10,6 +10,7 @@ import requests
 
 # Signature algorithm.
 def calc_sign(msg, key):
+    """Calculate signature for request."""
     sign = (
         hmac.new(
             msg=bytes(msg, "latin-1"),
@@ -36,6 +37,7 @@ class TuyaCloudApi:
         self._device_list = {}
 
     def generate_payload(self, method, t, url, headers, body=None):
+        """Generate signed payload for requests."""
         payload = self._client_id + self._access_token + t
 
         payload += method + "\n"
diff --git a/custom_components/localtuya/common.py b/custom_components/localtuya/common.py
index d3e691b..372b61e 100644
--- a/custom_components/localtuya/common.py
+++ b/custom_components/localtuya/common.py
@@ -218,6 +218,7 @@ class TuyaDevice(pytuya.TuyaListener, pytuya.ContextualLogger):
         self._connect_task = None
 
     async def update_local_key(self):
+        """Retrieve updated local_key from Cloud API and update the config_entry."""
         dev_id = self._dev_config_entry[CONF_DEVICE_ID]
         await self._hass.data[DOMAIN][DATA_CLOUD].async_get_devices_list()
         cloud_devs = self._hass.data[DOMAIN][DATA_CLOUD]._device_list
diff --git a/custom_components/localtuya/config_flow.py b/custom_components/localtuya/config_flow.py
index 3de2284..605ea03 100644
--- a/custom_components/localtuya/config_flow.py
+++ b/custom_components/localtuya/config_flow.py
@@ -593,6 +593,7 @@ class LocalTuyaOptionsFlowHandler(config_entries.OptionsFlow):
         return self.async_show_form(step_id="pick_entity_type", data_schema=schema)
 
     def available_dps_strings(self):
+        """Return list of DPs use by the device's entities."""
         available_dps = []
         used_dps = [str(entity[CONF_ID]) for entity in self.entities]
         for dp_string in self.dps_strings:
diff --git a/requirements_test.txt b/requirements_test.txt
index ca811a0..d803b74 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -1,4 +1,4 @@
-black==21.4b0
+black==22.3.0
 codespell==2.0.0
 flake8==3.9.2
 mypy==0.901
@@ -7,4 +7,3 @@ cryptography==3.3.2
 pylint==2.8.2
 pylint-strict-informational==0.1
 homeassistant==2022.5.1
-tox==3.25.0
diff --git a/tox.ini b/tox.ini
index 033e723..0a642b7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,7 +27,7 @@ ignore_errors = True
 deps =
     {[testenv]deps}
 commands =
-    codespell -q 4 -L {[tox]cs_exclude_words} --skip="*.pyc,*.pyi,*~" custom_components
+    codespell -q 4 -L {[tox]cs_exclude_words} --skip="*.pyc,*.pyi,*~,*.json" custom_components
     flake8 custom_components
     black --fast --check .
     pydocstyle -v custom_components