diff --git a/homeassistant/components/aftership/sensor.py b/homeassistant/components/aftership/sensor.py
index 9b8a5637de2..3f00c8c310d 100644
--- a/homeassistant/components/aftership/sensor.py
+++ b/homeassistant/components/aftership/sensor.py
@@ -191,7 +191,9 @@ class AfterShipSensor(Entity):
                     "name": name,
                     "tracking_number": track["tracking_number"],
                     "slug": track["slug"],
-                    "link": "%s%s/%s" % (BASE, track["slug"], track["tracking_number"]),
+                    "link": "{}{}/{}".format(
+                        BASE, track["slug"], track["tracking_number"]
+                    ),
                     "last_update": track["updated_at"],
                     "expected_delivery": track["expected_delivery"],
                     "status": track["tag"],
diff --git a/homeassistant/components/buienradar/sensor.py b/homeassistant/components/buienradar/sensor.py
index afa5013b339..235390d0013 100644
--- a/homeassistant/components/buienradar/sensor.py
+++ b/homeassistant/components/buienradar/sensor.py
@@ -255,10 +255,8 @@ class BrSensor(Entity):
     def uid(self, coordinates):
         """Generate a unique id using coordinates and sensor type."""
         # The combination of the location, name and sensor type is unique
-        return "%2.6f%2.6f%s" % (
-            coordinates[CONF_LATITUDE],
-            coordinates[CONF_LONGITUDE],
-            self.type,
+        return "{:2.6f}{:2.6f}{}".format(
+            coordinates[CONF_LATITUDE], coordinates[CONF_LONGITUDE], self.type,
         )
 
     @callback
diff --git a/homeassistant/components/config/zwave.py b/homeassistant/components/config/zwave.py
index eaed84fe24d..b792fcccec3 100644
--- a/homeassistant/components/config/zwave.py
+++ b/homeassistant/components/config/zwave.py
@@ -226,7 +226,7 @@ class ZWaveProtectionView(HomeAssistantView):
                 return self.json(protection_options)
             protections = node.get_protections()
             protection_options = {
-                "value_id": "{0:d}".format(list(protections)[0]),
+                "value_id": "{:d}".format(list(protections)[0]),
                 "selected": node.get_protection_item(list(protections)[0]),
                 "options": node.get_protection_items(list(protections)[0]),
             }
diff --git a/homeassistant/components/google_travel_time/sensor.py b/homeassistant/components/google_travel_time/sensor.py
index dd7d9bf8585..5e99b42b115 100644
--- a/homeassistant/components/google_travel_time/sensor.py
+++ b/homeassistant/components/google_travel_time/sensor.py
@@ -321,7 +321,7 @@ class GoogleTravelTimeSensor(Entity):
     def _get_location_from_attributes(entity):
         """Get the lat/long string from an entities attributes."""
         attr = entity.attributes
-        return "%s,%s" % (attr.get(ATTR_LATITUDE), attr.get(ATTR_LONGITUDE))
+        return "{},{}".format(attr.get(ATTR_LATITUDE), attr.get(ATTR_LONGITUDE))
 
     def _resolve_zone(self, friendly_name):
         entities = self._hass.states.all()
diff --git a/homeassistant/components/hdmi_cec/media_player.py b/homeassistant/components/hdmi_cec/media_player.py
index 42c5f0b456c..9b130f91b72 100644
--- a/homeassistant/components/hdmi_cec/media_player.py
+++ b/homeassistant/components/hdmi_cec/media_player.py
@@ -67,7 +67,9 @@ class CecPlayerDevice(CecDevice, MediaPlayerDevice):
     def __init__(self, device, logical) -> None:
         """Initialize the HDMI device."""
         CecDevice.__init__(self, device, logical)
-        self.entity_id = "%s.%s_%s" % (DOMAIN, "hdmi", hex(self._logical_address)[2:])
+        self.entity_id = "{}.{}_{}".format(
+            DOMAIN, "hdmi", hex(self._logical_address)[2:]
+        )
 
     def send_keypress(self, key):
         """Send keypress to CEC adapter."""
diff --git a/homeassistant/components/hdmi_cec/switch.py b/homeassistant/components/hdmi_cec/switch.py
index 53384397cf4..a4ef91dee8f 100644
--- a/homeassistant/components/hdmi_cec/switch.py
+++ b/homeassistant/components/hdmi_cec/switch.py
@@ -28,7 +28,9 @@ class CecSwitchDevice(CecDevice, SwitchDevice):
     def __init__(self, device, logical) -> None:
         """Initialize the HDMI device."""
         CecDevice.__init__(self, device, logical)
-        self.entity_id = "%s.%s_%s" % (DOMAIN, "hdmi", hex(self._logical_address)[2:])
+        self.entity_id = "{}.{}_{}".format(
+            DOMAIN, "hdmi", hex(self._logical_address)[2:]
+        )
 
     def turn_on(self, **kwargs) -> None:
         """Turn device on."""
diff --git a/homeassistant/components/nest/sensor.py b/homeassistant/components/nest/sensor.py
index 225caee0a90..064c78917e1 100644
--- a/homeassistant/components/nest/sensor.py
+++ b/homeassistant/components/nest/sensor.py
@@ -203,6 +203,6 @@ class NestTempSensor(NestSensorDevice):
 
         if isinstance(temp, tuple):
             low, high = temp
-            self._state = "%s-%s" % (int(low), int(high))
+            self._state = "{}-{}".format(int(low), int(high))
         else:
             self._state = round(temp, 1)
diff --git a/homeassistant/components/notion/__init__.py b/homeassistant/components/notion/__init__.py
index e9c45c62816..d608199f6fc 100644
--- a/homeassistant/components/notion/__init__.py
+++ b/homeassistant/components/notion/__init__.py
@@ -255,7 +255,7 @@ class NotionEntity(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{0}: {1}".format(
+        return "{}: {}".format(
             self._notion.sensors[self._sensor_id]["name"], self._name
         )
 
@@ -268,7 +268,7 @@ class NotionEntity(Entity):
     def unique_id(self):
         """Return a unique, unchanging string that represents this sensor."""
         task = self._notion.tasks[self._task_id]
-        return "{0}_{1}".format(self._sensor_id, task["task_type"])
+        return "{}_{}".format(self._sensor_id, task["task_type"])
 
     async def _update_bridge_id(self):
         """Update the entity's bridge ID if it has changed.
diff --git a/homeassistant/components/openalpr_cloud/image_processing.py b/homeassistant/components/openalpr_cloud/image_processing.py
index 64ba0d83844..13d8cf75e7c 100644
--- a/homeassistant/components/openalpr_cloud/image_processing.py
+++ b/homeassistant/components/openalpr_cloud/image_processing.py
@@ -86,7 +86,7 @@ class OpenAlprCloudEntity(ImageProcessingAlprEntity):
         if name:
             self._name = name
         else:
-            self._name = "OpenAlpr {0}".format(split_entity_id(camera_entity)[1])
+            self._name = "OpenAlpr {}".format(split_entity_id(camera_entity)[1])
 
     @property
     def confidence(self):
diff --git a/homeassistant/components/openalpr_local/image_processing.py b/homeassistant/components/openalpr_local/image_processing.py
index df7b235a224..b2e90ad5597 100644
--- a/homeassistant/components/openalpr_local/image_processing.py
+++ b/homeassistant/components/openalpr_local/image_processing.py
@@ -161,7 +161,7 @@ class OpenAlprLocalEntity(ImageProcessingAlprEntity):
         if name:
             self._name = name
         else:
-            self._name = "OpenAlpr {0}".format(split_entity_id(camera_entity)[1])
+            self._name = "OpenAlpr {}".format(split_entity_id(camera_entity)[1])
 
     @property
     def confidence(self):
diff --git a/homeassistant/components/opencv/image_processing.py b/homeassistant/components/opencv/image_processing.py
index 4a1b830a324..8e300c77465 100644
--- a/homeassistant/components/opencv/image_processing.py
+++ b/homeassistant/components/opencv/image_processing.py
@@ -132,7 +132,7 @@ class OpenCVImageProcessor(ImageProcessingEntity):
         if name:
             self._name = name
         else:
-            self._name = "OpenCV {0}".format(split_entity_id(camera_entity)[1])
+            self._name = "OpenCV {}".format(split_entity_id(camera_entity)[1])
         self._classifiers = classifiers
         self._matches = {}
         self._total_matches = 0
diff --git a/homeassistant/components/openuv/__init__.py b/homeassistant/components/openuv/__init__.py
index 008b46d96f2..df4ff9735c3 100644
--- a/homeassistant/components/openuv/__init__.py
+++ b/homeassistant/components/openuv/__init__.py
@@ -82,7 +82,7 @@ async def async_setup(hass, config):
 
     conf = config[DOMAIN]
 
-    identifier = "{0}, {1}".format(
+    identifier = "{}, {}".format(
         conf.get(CONF_LATITUDE, hass.config.latitude),
         conf.get(CONF_LONGITUDE, hass.config.longitude),
     )
diff --git a/homeassistant/components/openuv/config_flow.py b/homeassistant/components/openuv/config_flow.py
index 82873861fb1..402f6514178 100644
--- a/homeassistant/components/openuv/config_flow.py
+++ b/homeassistant/components/openuv/config_flow.py
@@ -20,7 +20,7 @@ from .const import DOMAIN
 def configured_instances(hass):
     """Return a set of configured OpenUV instances."""
     return set(
-        "{0}, {1}".format(
+        "{}, {}".format(
             entry.data.get(CONF_LATITUDE, hass.config.latitude),
             entry.data.get(CONF_LONGITUDE, hass.config.longitude),
         )
@@ -64,7 +64,7 @@ class OpenUvFlowHandler(config_entries.ConfigFlow):
         if not user_input:
             return await self._show_form()
 
-        identifier = "{0}, {1}".format(
+        identifier = "{}, {}".format(
             user_input.get(CONF_LATITUDE, self.hass.config.latitude),
             user_input.get(CONF_LONGITUDE, self.hass.config.longitude),
         )
diff --git a/homeassistant/components/qrcode/image_processing.py b/homeassistant/components/qrcode/image_processing.py
index 018f074a6d2..71bb67f0753 100644
--- a/homeassistant/components/qrcode/image_processing.py
+++ b/homeassistant/components/qrcode/image_processing.py
@@ -34,7 +34,7 @@ class QrEntity(ImageProcessingEntity):
         if name:
             self._name = name
         else:
-            self._name = "QR {0}".format(split_entity_id(camera_entity)[1])
+            self._name = "QR {}".format(split_entity_id(camera_entity)[1])
         self._state = None
 
     @property
diff --git a/homeassistant/components/raincloud/__init__.py b/homeassistant/components/raincloud/__init__.py
index 971b8174993..cc42bdc54b8 100644
--- a/homeassistant/components/raincloud/__init__.py
+++ b/homeassistant/components/raincloud/__init__.py
@@ -142,7 +142,7 @@ class RainCloudEntity(Entity):
         """Initialize the RainCloud entity."""
         self.data = data
         self._sensor_type = sensor_type
-        self._name = "{0} {1}".format(self.data.name, KEY_MAP.get(self._sensor_type))
+        self._name = "{} {}".format(self.data.name, KEY_MAP.get(self._sensor_type))
         self._state = None
 
     @property
diff --git a/homeassistant/components/rainmachine/__init__.py b/homeassistant/components/rainmachine/__init__.py
index 92c14d0e0cb..03dc49d7475 100644
--- a/homeassistant/components/rainmachine/__init__.py
+++ b/homeassistant/components/rainmachine/__init__.py
@@ -426,7 +426,7 @@ class RainMachineEntity(Entity):
             "identifiers": {(DOMAIN, self.rainmachine.controller.mac)},
             "name": self.rainmachine.controller.name,
             "manufacturer": "RainMachine",
-            "model": "Version {0} (API: {1})".format(
+            "model": "Version {} (API: {})".format(
                 self.rainmachine.controller.hardware_version,
                 self.rainmachine.controller.api_version,
             ),
diff --git a/homeassistant/components/rainmachine/binary_sensor.py b/homeassistant/components/rainmachine/binary_sensor.py
index 409ad0c9980..40802af2bfa 100644
--- a/homeassistant/components/rainmachine/binary_sensor.py
+++ b/homeassistant/components/rainmachine/binary_sensor.py
@@ -120,7 +120,7 @@ class RainMachineBinarySensor(RainMachineEntity, BinarySensorDevice):
     @property
     def unique_id(self) -> str:
         """Return a unique, Home Assistant friendly identifier for this entity."""
-        return "{0}_{1}".format(
+        return "{}_{}".format(
             self.rainmachine.device_mac.replace(":", ""), self._sensor_type
         )
 
diff --git a/homeassistant/components/rainmachine/sensor.py b/homeassistant/components/rainmachine/sensor.py
index 371ba00dfd0..287ce29a3cc 100644
--- a/homeassistant/components/rainmachine/sensor.py
+++ b/homeassistant/components/rainmachine/sensor.py
@@ -132,7 +132,7 @@ class RainMachineSensor(RainMachineEntity):
     @property
     def unique_id(self) -> str:
         """Return a unique, Home Assistant friendly identifier for this entity."""
-        return "{0}_{1}".format(
+        return "{}_{}".format(
             self.rainmachine.device_mac.replace(":", ""), self._sensor_type
         )
 
diff --git a/homeassistant/components/rainmachine/switch.py b/homeassistant/components/rainmachine/switch.py
index 264de1d6782..fd36e23cb0e 100644
--- a/homeassistant/components/rainmachine/switch.py
+++ b/homeassistant/components/rainmachine/switch.py
@@ -142,7 +142,7 @@ class RainMachineSwitch(RainMachineEntity, SwitchDevice):
     @property
     def unique_id(self) -> str:
         """Return a unique, Home Assistant friendly identifier for this entity."""
-        return "{0}_{1}_{2}".format(
+        return "{}_{}_{}".format(
             self.rainmachine.device_mac.replace(":", ""),
             self._switch_type,
             self._rainmachine_entity_id,
@@ -219,7 +219,7 @@ class RainMachineProgram(RainMachineSwitch):
 
         try:
             next_run = datetime.strptime(
-                "{0} {1}".format(
+                "{} {}".format(
                     self._switch_data["nextRun"], self._switch_data["startTime"]
                 ),
                 "%Y-%m-%d %H:%M",
diff --git a/homeassistant/components/ring/binary_sensor.py b/homeassistant/components/ring/binary_sensor.py
index 321b668f8aa..385d8a4f955 100644
--- a/homeassistant/components/ring/binary_sensor.py
+++ b/homeassistant/components/ring/binary_sensor.py
@@ -47,9 +47,7 @@ class RingBinarySensor(RingEntityMixin, BinarySensorDevice):
         super().__init__(config_entry_id, device)
         self._ring = ring
         self._sensor_type = sensor_type
-        self._name = "{0} {1}".format(
-            self._device.name, SENSOR_TYPES.get(sensor_type)[0]
-        )
+        self._name = "{} {}".format(self._device.name, SENSOR_TYPES.get(sensor_type)[0])
         self._device_class = SENSOR_TYPES.get(sensor_type)[2]
         self._state = None
         self._unique_id = f"{device.id}-{sensor_type}"
diff --git a/homeassistant/components/ring/sensor.py b/homeassistant/components/ring/sensor.py
index 84edaf67c22..260b4170745 100644
--- a/homeassistant/components/ring/sensor.py
+++ b/homeassistant/components/ring/sensor.py
@@ -46,9 +46,7 @@ class RingSensor(RingEntityMixin, Entity):
         self._extra = None
         self._icon = "mdi:{}".format(SENSOR_TYPES.get(sensor_type)[3])
         self._kind = SENSOR_TYPES.get(sensor_type)[4]
-        self._name = "{0} {1}".format(
-            self._device.name, SENSOR_TYPES.get(sensor_type)[0]
-        )
+        self._name = "{} {}".format(self._device.name, SENSOR_TYPES.get(sensor_type)[0])
         self._unique_id = f"{device.id}-{sensor_type}"
 
     @property
diff --git a/homeassistant/components/roku/media_player.py b/homeassistant/components/roku/media_player.py
index ba923f0fdd2..e26cce46ee2 100644
--- a/homeassistant/components/roku/media_player.py
+++ b/homeassistant/components/roku/media_player.py
@@ -153,8 +153,8 @@ class RokuDevice(MediaPlayerDevice):
         if self.current_app.id is None:
             return None
 
-        return "http://{0}:{1}/query/icon/{2}".format(
-            self.ip_address, DEFAULT_PORT, self.current_app.id
+        return (
+            f"http://{self.ip_address}:{DEFAULT_PORT}/query/icon/{self.current_app.id}"
         )
 
     @property
diff --git a/homeassistant/components/seven_segments/image_processing.py b/homeassistant/components/seven_segments/image_processing.py
index 315b5c39fec..4515ec7441b 100644
--- a/homeassistant/components/seven_segments/image_processing.py
+++ b/homeassistant/components/seven_segments/image_processing.py
@@ -69,14 +69,12 @@ class ImageProcessingSsocr(ImageProcessingEntity):
         if name:
             self._name = name
         else:
-            self._name = "SevenSegment OCR {0}".format(
-                split_entity_id(camera_entity)[1]
-            )
+            self._name = "SevenSegment OCR {}".format(split_entity_id(camera_entity)[1])
         self._state = None
 
         self.filepath = os.path.join(
             self.hass.config.config_dir,
-            "ssocr-{0}.png".format(self._name.replace(" ", "_")),
+            "ssocr-{}.png".format(self._name.replace(" ", "_")),
         )
         crop = [
             "crop",
diff --git a/homeassistant/components/seventeentrack/sensor.py b/homeassistant/components/seventeentrack/sensor.py
index 000019abb51..53b16944cb2 100644
--- a/homeassistant/components/seventeentrack/sensor.py
+++ b/homeassistant/components/seventeentrack/sensor.py
@@ -130,7 +130,7 @@ class SeventeenTrackSummarySensor(Entity):
     @property
     def unique_id(self):
         """Return a unique, Home Assistant friendly identifier for this entity."""
-        return "summary_{0}_{1}".format(self._data.account_id, slugify(self._status))
+        return "summary_{}_{}".format(self._data.account_id, slugify(self._status))
 
     @property
     def unit_of_measurement(self):
diff --git a/homeassistant/components/skybell/binary_sensor.py b/homeassistant/components/skybell/binary_sensor.py
index 776281e1510..f0df663eba3 100644
--- a/homeassistant/components/skybell/binary_sensor.py
+++ b/homeassistant/components/skybell/binary_sensor.py
@@ -51,7 +51,7 @@ class SkybellBinarySensor(SkybellDevice, BinarySensorDevice):
         """Initialize a binary sensor for a Skybell device."""
         super().__init__(device)
         self._sensor_type = sensor_type
-        self._name = "{0} {1}".format(
+        self._name = "{} {}".format(
             self._device.name, SENSOR_TYPES[self._sensor_type][0]
         )
         self._device_class = SENSOR_TYPES[self._sensor_type][1]
diff --git a/homeassistant/components/skybell/sensor.py b/homeassistant/components/skybell/sensor.py
index 7d266b7d3f6..24b63b6271c 100644
--- a/homeassistant/components/skybell/sensor.py
+++ b/homeassistant/components/skybell/sensor.py
@@ -49,7 +49,7 @@ class SkybellSensor(SkybellDevice):
         super().__init__(device)
         self._sensor_type = sensor_type
         self._icon = "mdi:{}".format(SENSOR_TYPES[self._sensor_type][1])
-        self._name = "{0} {1}".format(
+        self._name = "{} {}".format(
             self._device.name, SENSOR_TYPES[self._sensor_type][0]
         )
         self._state = None
diff --git a/homeassistant/components/skybell/switch.py b/homeassistant/components/skybell/switch.py
index e5a6975ddbb..03ea74a2340 100644
--- a/homeassistant/components/skybell/switch.py
+++ b/homeassistant/components/skybell/switch.py
@@ -48,7 +48,7 @@ class SkybellSwitch(SkybellDevice, SwitchDevice):
         """Initialize a light for a Skybell device."""
         super().__init__(device)
         self._switch_type = switch_type
-        self._name = "{0} {1}".format(
+        self._name = "{} {}".format(
             self._device.name, SWITCH_TYPES[self._switch_type][0]
         )
 
diff --git a/homeassistant/components/starlingbank/sensor.py b/homeassistant/components/starlingbank/sensor.py
index 1e046192347..20fa646ce41 100644
--- a/homeassistant/components/starlingbank/sensor.py
+++ b/homeassistant/components/starlingbank/sensor.py
@@ -75,7 +75,7 @@ class StarlingBalanceSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{0} {1}".format(
+        return "{} {}".format(
             self._account_name, self._balance_data_type.replace("_", " ").capitalize()
         )
 
diff --git a/homeassistant/components/statsd/__init__.py b/homeassistant/components/statsd/__init__.py
index 79065f7ba53..7ca3068f003 100644
--- a/homeassistant/components/statsd/__init__.py
+++ b/homeassistant/components/statsd/__init__.py
@@ -79,7 +79,7 @@ def setup(hass, config):
             # Send attribute values
             for key, value in states.items():
                 if isinstance(value, (float, int)):
-                    stat = "%s.%s" % (state.entity_id, key.replace(" ", "_"))
+                    stat = "{}.{}".format(state.entity_id, key.replace(" ", "_"))
                     statsd_client.gauge(stat, value, sample_rate)
 
         else:
diff --git a/homeassistant/components/swiss_hydrological_data/sensor.py b/homeassistant/components/swiss_hydrological_data/sensor.py
index d4624e82bb7..61423312b2a 100644
--- a/homeassistant/components/swiss_hydrological_data/sensor.py
+++ b/homeassistant/components/swiss_hydrological_data/sensor.py
@@ -97,7 +97,7 @@ class SwissHydrologicalDataSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{0} {1}".format(self._data["water-body-name"], self._condition)
+        return "{} {}".format(self._data["water-body-name"], self._condition)
 
     @property
     def unique_id(self) -> str:
diff --git a/homeassistant/components/tensorflow/image_processing.py b/homeassistant/components/tensorflow/image_processing.py
index 3638cbafb9f..b003fef56c0 100644
--- a/homeassistant/components/tensorflow/image_processing.py
+++ b/homeassistant/components/tensorflow/image_processing.py
@@ -168,7 +168,7 @@ class TensorFlowImageProcessor(ImageProcessingEntity):
         if name:
             self._name = name
         else:
-            self._name = "TensorFlow {0}".format(split_entity_id(camera_entity)[1])
+            self._name = "TensorFlow {}".format(split_entity_id(camera_entity)[1])
         self._session = session
         self._graph = detection_graph
         self._category_index = category_index
@@ -270,7 +270,7 @@ class TensorFlowImageProcessor(ImageProcessingEntity):
 
             # Draw detected objects
             for instance in values:
-                label = "{0} {1:.1f}%".format(category, instance["score"])
+                label = "{} {:.1f}%".format(category, instance["score"])
                 draw_box(
                     draw, instance["box"], img_width, img_height, label, (255, 255, 0)
                 )
diff --git a/homeassistant/components/tile/device_tracker.py b/homeassistant/components/tile/device_tracker.py
index 8bc4fb11cdf..6cfe6121ccb 100644
--- a/homeassistant/components/tile/device_tracker.py
+++ b/homeassistant/components/tile/device_tracker.py
@@ -121,7 +121,7 @@ class TileScanner:
 
         for tile in tiles:
             await self._async_see(
-                dev_id="tile_{0}".format(slugify(tile["tile_uuid"])),
+                dev_id="tile_{}".format(slugify(tile["tile_uuid"])),
                 gps=(
                     tile["last_tile_state"]["latitude"],
                     tile["last_tile_state"]["longitude"],
diff --git a/homeassistant/components/travisci/sensor.py b/homeassistant/components/travisci/sensor.py
index ffbe5239cc9..c2ce599f5c3 100644
--- a/homeassistant/components/travisci/sensor.py
+++ b/homeassistant/components/travisci/sensor.py
@@ -106,9 +106,7 @@ class TravisCISensor(Entity):
         self._user = user
         self._branch = branch
         self._state = None
-        self._name = "{0} {1}".format(
-            self._repo_name, SENSOR_TYPES[self._sensor_type][0]
-        )
+        self._name = "{} {}".format(self._repo_name, SENSOR_TYPES[self._sensor_type][0])
 
     @property
     def name(self):
diff --git a/homeassistant/components/withings/common.py b/homeassistant/components/withings/common.py
index 9cba055bac4..3a9d1d52751 100644
--- a/homeassistant/components/withings/common.py
+++ b/homeassistant/components/withings/common.py
@@ -108,7 +108,7 @@ class ConfigEntryWithingsApi(AbstractWithingsApi):
             partial(
                 requests.request,
                 method,
-                "%s/%s" % (self.URL, path),
+                f"{self.URL}/{path}",
                 params=params,
                 headers={
                     "Authorization": "Bearer %s"
diff --git a/homeassistant/components/xiaomi/camera.py b/homeassistant/components/xiaomi/camera.py
index cc85f17146b..2b249c7b7c8 100644
--- a/homeassistant/components/xiaomi/camera.py
+++ b/homeassistant/components/xiaomi/camera.py
@@ -136,7 +136,7 @@ class XiaomiCamera(Camera):
         else:
             video = videos[-1]
 
-        return "ftp://{0}:{1}@{2}:{3}{4}/{5}".format(
+        return "ftp://{}:{}@{}:{}{}/{}".format(
             self.user, self.passwd, host, self.port, ftp.pwd(), video
         )
 
diff --git a/homeassistant/components/yeelight/__init__.py b/homeassistant/components/yeelight/__init__.py
index eae1cd32c06..1e0fe841cac 100644
--- a/homeassistant/components/yeelight/__init__.py
+++ b/homeassistant/components/yeelight/__init__.py
@@ -147,7 +147,7 @@ def setup(hass, config):
     def device_discovered(_, info):
         _LOGGER.debug("Adding autodetected %s", info["hostname"])
 
-        name = "yeelight_%s_%s" % (info["device_type"], info["properties"]["mac"])
+        name = "yeelight_{}_{}".format(info["device_type"], info["properties"]["mac"])
 
         device_config = DEVICE_SCHEMA({CONF_NAME: name})
 
diff --git a/homeassistant/components/yi/camera.py b/homeassistant/components/yi/camera.py
index 6e49d287186..658cc3a23ee 100644
--- a/homeassistant/components/yi/camera.py
+++ b/homeassistant/components/yi/camera.py
@@ -110,7 +110,7 @@ class YiCamera(Camera):
 
             await ftp.quit()
             self._is_on = True
-            return "ftp://{0}:{1}@{2}:{3}{4}/{5}/{6}".format(
+            return "ftp://{}:{}@{}:{}{}/{}/{}".format(
                 self.user,
                 self.passwd,
                 self.host,
diff --git a/homeassistant/components/yr/sensor.py b/homeassistant/components/yr/sensor.py
index 9955a650cd3..2061c061dd0 100644
--- a/homeassistant/components/yr/sensor.py
+++ b/homeassistant/components/yr/sensor.py
@@ -139,7 +139,7 @@ class YrSensor(Entity):
             return None
         return (
             "https://api.met.no/weatherapi/weathericon/1.1/"
-            "?symbol={0};content_type=image/png".format(self._state)
+            f"?symbol={self._state};content_type=image/png"
         )
 
     @property
diff --git a/homeassistant/util/color.py b/homeassistant/util/color.py
index b56ecbbaa89..965b5950c93 100644
--- a/homeassistant/util/color.py
+++ b/homeassistant/util/color.py
@@ -424,7 +424,7 @@ def color_rgbw_to_rgb(r: int, g: int, b: int, w: int) -> Tuple[int, int, int]:
 
 def color_rgb_to_hex(r: int, g: int, b: int) -> str:
     """Return a RGB color from a hex color string."""
-    return "{0:02x}{1:02x}{2:02x}".format(round(r), round(g), round(b))
+    return "{:02x}{:02x}{:02x}".format(round(r), round(g), round(b))
 
 
 def rgb_hex_to_rgb_list(hex_string: str) -> List[int]: