diff --git a/homeassistant/components/rachio/__init__.py b/homeassistant/components/rachio/__init__.py
index 0d582b0c2e99..2030512ab313 100644
--- a/homeassistant/components/rachio/__init__.py
+++ b/homeassistant/components/rachio/__init__.py
@@ -226,7 +226,7 @@ class RachioIro:
 
     def __str__(self) -> str:
         """Display the controller as a string."""
-        return 'Rachio controller "{}"'.format(self.name)
+        return f'Rachio controller "{self.name}"'
 
     @property
     def controller_id(self) -> str:
diff --git a/homeassistant/components/rachio/binary_sensor.py b/homeassistant/components/rachio/binary_sensor.py
index 01d38a931c47..f74e3ca18021 100644
--- a/homeassistant/components/rachio/binary_sensor.py
+++ b/homeassistant/components/rachio/binary_sensor.py
@@ -87,12 +87,12 @@ class RachioControllerOnlineBinarySensor(RachioControllerBinarySensor):
     @property
     def name(self) -> str:
         """Return the name of this sensor including the controller name."""
-        return "{} online".format(self._controller.name)
+        return f"{self._controller.name} online"
 
     @property
     def unique_id(self) -> str:
         """Return a unique id for this entity."""
-        return "{}-online".format(self._controller.controller_id)
+        return f"{self._controller.controller_id}-online"
 
     @property
     def device_class(self) -> str:
diff --git a/homeassistant/components/rachio/switch.py b/homeassistant/components/rachio/switch.py
index b65e6bf60442..80c227a6df69 100644
--- a/homeassistant/components/rachio/switch.py
+++ b/homeassistant/components/rachio/switch.py
@@ -72,7 +72,7 @@ class RachioSwitch(SwitchDevice):
     @property
     def name(self) -> str:
         """Get a name for this switch."""
-        return "Switch on {}".format(self._controller.name)
+        return f"Switch on {self._controller.name}"
 
     @property
     def is_on(self) -> bool:
@@ -113,12 +113,12 @@ class RachioStandbySwitch(RachioSwitch):
     @property
     def name(self) -> str:
         """Return the name of the standby switch."""
-        return "{} in standby mode".format(self._controller.name)
+        return f"{self._controller.name} in standby mode"
 
     @property
     def unique_id(self) -> str:
         """Return a unique id by combining controller id and purpose."""
-        return "{}-standby".format(self._controller.controller_id)
+        return f"{self._controller.controller_id}-standby"
 
     @property
     def icon(self) -> str:
@@ -183,7 +183,7 @@ class RachioZone(RachioSwitch):
     @property
     def unique_id(self) -> str:
         """Return a unique id by combining controller id and zone number."""
-        return "{}-zone-{}".format(self._controller.controller_id, self.zone_id)
+        return f"{self._controller.controller_id}-zone-{self.zone_id}"
 
     @property
     def icon(self) -> str:
diff --git a/homeassistant/components/rainbird/switch.py b/homeassistant/components/rainbird/switch.py
index a1b82bc1af74..868e8ff4c7d6 100644
--- a/homeassistant/components/rainbird/switch.py
+++ b/homeassistant/components/rainbird/switch.py
@@ -53,7 +53,7 @@ class RainBirdSwitch(SwitchDevice):
         self._rainbird = rb
         self._devid = dev_id
         self._zone = int(dev.get(CONF_ZONE))
-        self._name = dev.get(CONF_FRIENDLY_NAME, "Sprinkler {}".format(self._zone))
+        self._name = dev.get(CONF_FRIENDLY_NAME, f"Sprinkler {self._zone}")
         self._state = None
         self._duration = dev.get(CONF_TRIGGER_TIME)
         self._attributes = {"duration": self._duration, "zone": self._zone}
diff --git a/homeassistant/components/rainmachine/__init__.py b/homeassistant/components/rainmachine/__init__.py
index b04384dc81dd..183872087a72 100644
--- a/homeassistant/components/rainmachine/__init__.py
+++ b/homeassistant/components/rainmachine/__init__.py
@@ -41,9 +41,9 @@ _LOGGER = logging.getLogger(__name__)
 
 DATA_LISTENER = "listener"
 
-PROGRAM_UPDATE_TOPIC = "{0}_program_update".format(DOMAIN)
-SENSOR_UPDATE_TOPIC = "{0}_data_update".format(DOMAIN)
-ZONE_UPDATE_TOPIC = "{0}_zone_update".format(DOMAIN)
+PROGRAM_UPDATE_TOPIC = f"{DOMAIN}_program_update"
+SENSOR_UPDATE_TOPIC = f"{DOMAIN}_data_update"
+ZONE_UPDATE_TOPIC = f"{DOMAIN}_zone_update"
 
 CONF_CONTROLLERS = "controllers"
 CONF_PROGRAM_ID = "program_id"
diff --git a/homeassistant/components/recollect_waste/sensor.py b/homeassistant/components/recollect_waste/sensor.py
index 0c3833528dc6..118b6fb37097 100644
--- a/homeassistant/components/recollect_waste/sensor.py
+++ b/homeassistant/components/recollect_waste/sensor.py
@@ -66,7 +66,7 @@ class RecollectWasteSensor(Entity):
     @property
     def unique_id(self) -> str:
         """Return a unique ID."""
-        return "{}{}".format(self.client.place_id, self.client.service_id)
+        return f"{self.client.place_id}{self.client.service_id}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/reddit/sensor.py b/homeassistant/components/reddit/sensor.py
index 0e95bea9091d..f9c8140f60db 100644
--- a/homeassistant/components/reddit/sensor.py
+++ b/homeassistant/components/reddit/sensor.py
@@ -94,7 +94,7 @@ class RedditSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "reddit_{}".format(self._subreddit)
+        return f"reddit_{self._subreddit}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/rejseplanen/sensor.py b/homeassistant/components/rejseplanen/sensor.py
index 3172e614166b..61cb319fd11e 100644
--- a/homeassistant/components/rejseplanen/sensor.py
+++ b/homeassistant/components/rejseplanen/sensor.py
@@ -220,7 +220,7 @@ class PublicTransportData:
                 and due_at_time is not None
                 and route is not None
             ):
-                due_at = "{} {}".format(due_at_date, due_at_time)
+                due_at = f"{due_at_date} {due_at_time}"
 
                 departure_data = {
                     ATTR_DUE_IN: due_in_minutes(due_at),
diff --git a/homeassistant/components/remember_the_milk/__init__.py b/homeassistant/components/remember_the_milk/__init__.py
index 3d340d9c07e6..c92a246da147 100644
--- a/homeassistant/components/remember_the_milk/__init__.py
+++ b/homeassistant/components/remember_the_milk/__init__.py
@@ -87,13 +87,13 @@ def _create_instance(
     component.add_entities([entity])
     hass.services.register(
         DOMAIN,
-        "{}_create_task".format(account_name),
+        f"{account_name}_create_task",
         entity.create_task,
         schema=SERVICE_SCHEMA_CREATE_TASK,
     )
     hass.services.register(
         DOMAIN,
-        "{}_complete_task".format(account_name),
+        f"{account_name}_complete_task",
         entity.complete_task,
         schema=SERVICE_SCHEMA_COMPLETE_TASK,
     )
@@ -137,7 +137,7 @@ def _register_new_account(
         configurator.request_done(request_id)
 
     request_id = configurator.async_request_config(
-        "{} - {}".format(DOMAIN, account_name),
+        f"{DOMAIN} - {account_name}",
         callback=register_account_callback,
         description="You need to log in to Remember The Milk to"
         + "connect your account. \n\n"
diff --git a/homeassistant/components/repetier/__init__.py b/homeassistant/components/repetier/__init__.py
index 1643966b33ee..6f72a6b7ddc5 100644
--- a/homeassistant/components/repetier/__init__.py
+++ b/homeassistant/components/repetier/__init__.py
@@ -239,7 +239,7 @@ class PrinterAPI:
                 info["name"] = printer.slug
                 info["printer_name"] = self.conf_name
 
-                known = "{}-{}".format(printer.slug, sensor_type)
+                known = f"{printer.slug}-{sensor_type}"
                 if known in self._known_entities:
                     continue
 
diff --git a/homeassistant/components/rflink/light.py b/homeassistant/components/rflink/light.py
index 56ae6f8675fb..682d45f8f420 100644
--- a/homeassistant/components/rflink/light.py
+++ b/homeassistant/components/rflink/light.py
@@ -300,7 +300,7 @@ class ToggleRflinkLight(SwitchableRflinkDevice, Light):
     @property
     def entity_id(self):
         """Return entity id."""
-        return "light.{}".format(self.name)
+        return f"light.{self.name}"
 
     def _handle_event(self, event):
         """Adjust state if Rflink picks up a remote command for this device."""
diff --git a/homeassistant/components/rfxtrx/__init__.py b/homeassistant/components/rfxtrx/__init__.py
index 0c9a98143c80..79b3054ecf27 100644
--- a/homeassistant/components/rfxtrx/__init__.py
+++ b/homeassistant/components/rfxtrx/__init__.py
@@ -106,7 +106,7 @@ def setup(hass, config):
             slugify(event.device.id_string.lower()),
             event.device.__class__.__name__,
             event.device.subtype,
-            "".join("{0:02x}".format(x) for x in event.data),
+            "".join(f"{x:02x}" for x in event.data),
         )
 
         # Callback to HA registered components.
@@ -270,7 +270,7 @@ def get_new_device(event, config, device):
     if not config[ATTR_AUTOMATIC_ADD]:
         return
 
-    pkt_id = "".join("{0:02x}".format(x) for x in event.data)
+    pkt_id = "".join(f"{x:02x}" for x in event.data)
     _LOGGER.debug(
         "Automatic add %s rfxtrx device (Class: %s Sub: %s Packet_id: %s)",
         device_id,
diff --git a/homeassistant/components/rfxtrx/binary_sensor.py b/homeassistant/components/rfxtrx/binary_sensor.py
index d4ed874156e9..8f1c7e6fa55f 100644
--- a/homeassistant/components/rfxtrx/binary_sensor.py
+++ b/homeassistant/components/rfxtrx/binary_sensor.py
@@ -116,7 +116,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
                     poss_id = slugify(poss_dev.event.device.id_string.lower())
                     _LOGGER.debug("Found possible matching device ID: %s", poss_id)
 
-            pkt_id = "".join("{0:02x}".format(x) for x in event.data)
+            pkt_id = "".join(f"{x:02x}" for x in event.data)
             sensor = RfxtrxBinarySensor(event, pkt_id)
             sensor.hass = hass
             rfxtrx.RFX_DEVICES[device_id] = sensor
diff --git a/homeassistant/components/rfxtrx/sensor.py b/homeassistant/components/rfxtrx/sensor.py
index 69397263a627..5941b00764b8 100644
--- a/homeassistant/components/rfxtrx/sensor.py
+++ b/homeassistant/components/rfxtrx/sensor.py
@@ -98,7 +98,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
         if not config[CONF_AUTOMATIC_ADD]:
             return
 
-        pkt_id = "".join("{0:02x}".format(x) for x in event.data)
+        pkt_id = "".join(f"{x:02x}" for x in event.data)
         _LOGGER.info("Automatic add rfxtrx.sensor: %s", pkt_id)
 
         data_type = ""
@@ -141,7 +141,7 @@ class RfxtrxSensor(Entity):
     @property
     def name(self):
         """Get the name of the sensor."""
-        return "{} {}".format(self._name, self.data_type)
+        return f"{self._name} {self.data_type}"
 
     @property
     def device_state_attributes(self):
diff --git a/homeassistant/components/ring/binary_sensor.py b/homeassistant/components/ring/binary_sensor.py
index 1b06a1d47d10..6806df0408fb 100644
--- a/homeassistant/components/ring/binary_sensor.py
+++ b/homeassistant/components/ring/binary_sensor.py
@@ -73,7 +73,7 @@ class RingBinarySensor(BinarySensorDevice):
         )
         self._device_class = SENSOR_TYPES.get(self._sensor_type)[2]
         self._state = None
-        self._unique_id = "{}-{}".format(self._data.id, self._sensor_type)
+        self._unique_id = f"{self._data.id}-{self._sensor_type}"
 
     @property
     def name(self):
diff --git a/homeassistant/components/ring/light.py b/homeassistant/components/ring/light.py
index bd7ea3a36797..5805114252e0 100644
--- a/homeassistant/components/ring/light.py
+++ b/homeassistant/components/ring/light.py
@@ -56,7 +56,7 @@ class RingLight(Light):
     @property
     def name(self):
         """Name of the light."""
-        return "{} light".format(self._device.name)
+        return f"{self._device.name} light"
 
     @property
     def unique_id(self):
diff --git a/homeassistant/components/ring/sensor.py b/homeassistant/components/ring/sensor.py
index 9950609c10fd..af661f4571c2 100644
--- a/homeassistant/components/ring/sensor.py
+++ b/homeassistant/components/ring/sensor.py
@@ -121,7 +121,7 @@ class RingSensor(Entity):
         )
         self._state = None
         self._tz = str(hass.config.time_zone)
-        self._unique_id = "{}-{}".format(self._data.id, self._sensor_type)
+        self._unique_id = f"{self._data.id}-{self._sensor_type}"
 
     async def async_added_to_hass(self):
         """Register callbacks."""
diff --git a/homeassistant/components/ring/switch.py b/homeassistant/components/ring/switch.py
index 3b6bd4ea0243..cbbecb1a4039 100644
--- a/homeassistant/components/ring/switch.py
+++ b/homeassistant/components/ring/switch.py
@@ -38,7 +38,7 @@ class BaseRingSwitch(SwitchDevice):
         """Initialize the switch."""
         self._device = device
         self._device_type = device_type
-        self._unique_id = "{}-{}".format(self._device.id, self._device_type)
+        self._unique_id = f"{self._device.id}-{self._device_type}"
 
     async def async_added_to_hass(self):
         """Register callbacks."""
@@ -53,7 +53,7 @@ class BaseRingSwitch(SwitchDevice):
     @property
     def name(self):
         """Name of the device."""
-        return "{} {}".format(self._device.name, self._device_type)
+        return f"{self._device.name} {self._device_type}"
 
     @property
     def unique_id(self):
diff --git a/homeassistant/components/roku/__init__.py b/homeassistant/components/roku/__init__.py
index e6dd05b93286..aa13814ee6b7 100644
--- a/homeassistant/components/roku/__init__.py
+++ b/homeassistant/components/roku/__init__.py
@@ -78,7 +78,7 @@ def scan_for_rokus(hass):
             "Name: {0}<br />Host: {1}<br />".format(
                 r_info.userdevicename
                 if r_info.userdevicename
-                else "{} {}".format(r_info.modelname, r_info.serial_num),
+                else f"{r_info.modelname} {r_info.serial_num}",
                 roku.host,
             )
         )
diff --git a/homeassistant/components/roku/media_player.py b/homeassistant/components/roku/media_player.py
index 03060361020c..d69b0eddb71d 100644
--- a/homeassistant/components/roku/media_player.py
+++ b/homeassistant/components/roku/media_player.py
@@ -92,7 +92,7 @@ class RokuDevice(MediaPlayerDevice):
         """Return the name of the device."""
         if self._device_info.user_device_name:
             return self._device_info.user_device_name
-        return "Roku {}".format(self._device_info.serial_num)
+        return f"Roku {self._device_info.serial_num}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/roku/remote.py b/homeassistant/components/roku/remote.py
index 0bb840e95313..f443b7e8e74e 100644
--- a/homeassistant/components/roku/remote.py
+++ b/homeassistant/components/roku/remote.py
@@ -36,7 +36,7 @@ class RokuRemote(remote.RemoteDevice):
         """Return the name of the device."""
         if self._device_info.user_device_name:
             return self._device_info.user_device_name
-        return "Roku {}".format(self._device_info.serial_num)
+        return f"Roku {self._device_info.serial_num}"
 
     @property
     def unique_id(self):
diff --git a/homeassistant/components/roomba/vacuum.py b/homeassistant/components/roomba/vacuum.py
index 766fd72cdbab..291658e19f4b 100644
--- a/homeassistant/components/roomba/vacuum.py
+++ b/homeassistant/components/roomba/vacuum.py
@@ -327,7 +327,7 @@ class RoombaVacuum(VacuumDevice):
             pos_y = pos_state.get("point", {}).get("y")
             theta = pos_state.get("theta")
             if all(item is not None for item in [pos_x, pos_y, theta]):
-                position = "({}, {}, {})".format(pos_x, pos_y, theta)
+                position = f"({pos_x}, {pos_y}, {theta})"
             self._state_attrs[ATTR_POSITION] = position
 
         # Not all Roombas have a bin full sensor
diff --git a/homeassistant/components/route53/__init__.py b/homeassistant/components/route53/__init__.py
index 906f09a56491..3dffc3ffd9e3 100644
--- a/homeassistant/components/route53/__init__.py
+++ b/homeassistant/components/route53/__init__.py
@@ -104,7 +104,7 @@ def _update_route53(
             {
                 "Action": "UPSERT",
                 "ResourceRecordSet": {
-                    "Name": "{}.{}".format(record, domain),
+                    "Name": f"{record}.{domain}",
                     "Type": "A",
                     "TTL": ttl,
                     "ResourceRecords": [{"Value": ipaddress}],
diff --git a/homeassistant/components/rova/sensor.py b/homeassistant/components/rova/sensor.py
index c39bf5ca4f3f..fe0b5dead84d 100644
--- a/homeassistant/components/rova/sensor.py
+++ b/homeassistant/components/rova/sensor.py
@@ -96,7 +96,7 @@ class RovaSensor(Entity):
     @property
     def name(self):
         """Return the name."""
-        return "{}_{}".format(self.platform_name, self.sensor_key)
+        return f"{self.platform_name}_{self.sensor_key}"
 
     @property
     def icon(self):
diff --git a/homeassistant/components/rtorrent/sensor.py b/homeassistant/components/rtorrent/sensor.py
index f2533e3dc862..ed16331e9128 100644
--- a/homeassistant/components/rtorrent/sensor.py
+++ b/homeassistant/components/rtorrent/sensor.py
@@ -79,7 +79,7 @@ class RTorrentSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{} {}".format(self.client_name, self._name)
+        return f"{self.client_name} {self._name}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/sabnzbd/sensor.py b/homeassistant/components/sabnzbd/sensor.py
index 642dd27b1d82..58624c758d9c 100644
--- a/homeassistant/components/sabnzbd/sensor.py
+++ b/homeassistant/components/sabnzbd/sensor.py
@@ -42,7 +42,7 @@ class SabnzbdSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{} {}".format(self._client_name, self._name)
+        return f"{self._client_name} {self._name}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/samsungtv/media_player.py b/homeassistant/components/samsungtv/media_player.py
index 934ee94e65df..2821a05261b3 100644
--- a/homeassistant/components/samsungtv/media_player.py
+++ b/homeassistant/components/samsungtv/media_player.py
@@ -84,7 +84,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
         tv_name = discovery_info.get("name")
         model = discovery_info.get("model_name")
         host = discovery_info.get("host")
-        name = "{} ({})".format(tv_name, model)
+        name = f"{tv_name} ({model})"
         port = DEFAULT_PORT
         timeout = DEFAULT_TIMEOUT
         mac = None
diff --git a/homeassistant/components/scsgate/__init__.py b/homeassistant/components/scsgate/__init__.py
index acb7f78a2aaf..739a2949d17a 100644
--- a/homeassistant/components/scsgate/__init__.py
+++ b/homeassistant/components/scsgate/__init__.py
@@ -77,11 +77,11 @@ class SCSGate:
         """Handle a messages seen on the bus."""
         from scsgate.messages import StateMessage, ScenarioTriggeredMessage
 
-        self._logger.debug("Received message {}".format(message))
+        self._logger.debug(f"Received message {message}")
         if not isinstance(message, StateMessage) and not isinstance(
             message, ScenarioTriggeredMessage
         ):
-            msg = "Ignored message {} - not relevant type".format(message)
+            msg = f"Ignored message {message} - not relevant type"
             self._logger.debug(msg)
             return
 
@@ -97,7 +97,7 @@ class SCSGate:
             try:
                 self._devices[message.entity].process_event(message)
             except Exception as exception:  # pylint: disable=broad-except
-                msg = "Exception while processing event: {}".format(exception)
+                msg = f"Exception while processing event: {exception}"
                 self._logger.error(msg)
         else:
             self._logger.info(
diff --git a/homeassistant/components/sense/sensor.py b/homeassistant/components/sense/sensor.py
index 8ad289b92000..36474620b03f 100644
--- a/homeassistant/components/sense/sensor.py
+++ b/homeassistant/components/sense/sensor.py
@@ -80,7 +80,7 @@ class Sense(Entity):
     def __init__(self, data, name, sensor_type, is_production, update_call):
         """Initialize the Sense sensor."""
         name_type = PRODUCTION_NAME if is_production else CONSUMPTION_NAME
-        self._name = "{} {}".format(name, name_type)
+        self._name = f"{name} {name_type}"
         self._data = data
         self._sensor_type = sensor_type
         self.update_sensor = update_call
diff --git a/homeassistant/components/serial_pm/sensor.py b/homeassistant/components/serial_pm/sensor.py
index 809526724877..1d46b05d46e0 100644
--- a/homeassistant/components/serial_pm/sensor.py
+++ b/homeassistant/components/serial_pm/sensor.py
@@ -51,7 +51,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
         if config.get(CONF_NAME) is not None:
             name = "{} PM{}".format(config.get(CONF_NAME), pmname)
         else:
-            name = "PM{}".format(pmname)
+            name = f"PM{pmname}"
         dev.append(ParticulateMatterSensor(coll, name, pmname))
 
     add_entities(dev)
diff --git a/homeassistant/components/seventeentrack/sensor.py b/homeassistant/components/seventeentrack/sensor.py
index 14539e342f18..33abe2f1f861 100644
--- a/homeassistant/components/seventeentrack/sensor.py
+++ b/homeassistant/components/seventeentrack/sensor.py
@@ -120,7 +120,7 @@ class SeventeenTrackSummarySensor(Entity):
     @property
     def name(self):
         """Return the name."""
-        return "Seventeentrack Packages {0}".format(self._status)
+        return f"Seventeentrack Packages {self._status}"
 
     @property
     def state(self):
@@ -203,7 +203,7 @@ class SeventeenTrackPackageSensor(Entity):
         name = self._friendly_name
         if not name:
             name = self._tracking_number
-        return "Seventeentrack Package: {0}".format(name)
+        return f"Seventeentrack Package: {name}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/shiftr/__init__.py b/homeassistant/components/shiftr/__init__.py
index a7e82ef66cf6..8e698d283cfc 100644
--- a/homeassistant/components/shiftr/__init__.py
+++ b/homeassistant/components/shiftr/__init__.py
@@ -69,10 +69,7 @@ def setup(hass, config):
             if state.attributes:
                 for attribute, data in state.attributes.items():
                     mqttc.publish(
-                        "/{}/{}".format(topic, attribute),
-                        str(data),
-                        qos=0,
-                        retain=False,
+                        f"/{topic}/{attribute}", str(data), qos=0, retain=False
                     )
         except RuntimeError:
             pass
diff --git a/homeassistant/components/shopping_list/__init__.py b/homeassistant/components/shopping_list/__init__.py
index 075d819655b3..3c9cb4391a73 100644
--- a/homeassistant/components/shopping_list/__init__.py
+++ b/homeassistant/components/shopping_list/__init__.py
@@ -196,7 +196,7 @@ class AddItemIntent(intent.IntentHandler):
         intent_obj.hass.data[DOMAIN].async_add(item)
 
         response = intent_obj.create_response()
-        response.async_set_speech("I've added {} to your shopping list".format(item))
+        response.async_set_speech(f"I've added {item} to your shopping list")
         intent_obj.hass.bus.async_fire(EVENT)
         return response
 
diff --git a/homeassistant/components/sigfox/sensor.py b/homeassistant/components/sigfox/sensor.py
index 0961017b65c1..b890880389c2 100644
--- a/homeassistant/components/sigfox/sensor.py
+++ b/homeassistant/components/sigfox/sensor.py
@@ -90,7 +90,7 @@ class SigfoxAPI:
         """Get the device_id of each device registered."""
         devices = []
         for unique_type in device_types:
-            location_url = "devicetypes/{}/devices".format(unique_type)
+            location_url = f"devicetypes/{unique_type}/devices"
             url = urljoin(API_URL, location_url)
             response = requests.get(url, auth=self._auth, timeout=10)
             devices_data = json.loads(response.text)["data"]
@@ -117,12 +117,12 @@ class SigfoxDevice(Entity):
         self._device_id = device_id
         self._auth = auth
         self._message_data = {}
-        self._name = "{}_{}".format(name, device_id)
+        self._name = f"{name}_{device_id}"
         self._state = None
 
     def get_last_message(self):
         """Return the last message from a device."""
-        device_url = "devices/{}/messages?limit=1".format(self._device_id)
+        device_url = f"devices/{self._device_id}/messages?limit=1"
         url = urljoin(API_URL, device_url)
         response = requests.get(url, auth=self._auth, timeout=10)
         data = json.loads(response.text)["data"][0]
diff --git a/homeassistant/components/sky_hub/device_tracker.py b/homeassistant/components/sky_hub/device_tracker.py
index eea97fb37fb0..c8969add244a 100644
--- a/homeassistant/components/sky_hub/device_tracker.py
+++ b/homeassistant/components/sky_hub/device_tracker.py
@@ -34,7 +34,7 @@ class SkyHubDeviceScanner(DeviceScanner):
         _LOGGER.info("Initialising Sky Hub")
         self.host = config.get(CONF_HOST, "192.168.1.254")
         self.last_results = {}
-        self.url = "http://{}/".format(self.host)
+        self.url = f"http://{self.host}/"
 
         # Test the router is accessible
         data = _get_skyhub_data(self.url)
diff --git a/homeassistant/components/skybell/camera.py b/homeassistant/components/skybell/camera.py
index 87cfdce6dfca..87dc3c0bf8d7 100644
--- a/homeassistant/components/skybell/camera.py
+++ b/homeassistant/components/skybell/camera.py
@@ -57,7 +57,7 @@ class SkybellCamera(SkybellDevice, Camera):
         SkybellDevice.__init__(self, device)
         Camera.__init__(self)
         if name is not None:
-            self._name = "{} {}".format(self._device.name, name)
+            self._name = f"{self._device.name} {name}"
         else:
             self._name = self._device.name
         self._url = None
diff --git a/homeassistant/components/sma/sensor.py b/homeassistant/components/sma/sensor.py
index 5b6bc57be9d6..56e10b03d2ad 100644
--- a/homeassistant/components/sma/sensor.py
+++ b/homeassistant/components/sma/sensor.py
@@ -50,7 +50,7 @@ def _check_sensor_schema(conf):
                 sensor,
             )
         elif sensor not in valid:
-            raise vol.Invalid("{} does not exist".format(sensor))
+            raise vol.Invalid(f"{sensor} does not exist")
     return conf
 
 
@@ -217,7 +217,7 @@ class SMAsensor(Entity):
         update = False
 
         for sens in self._sub_sensors:  # Can be remove from 0.99
-            newval = "{} {}".format(sens.value, sens.unit)
+            newval = f"{sens.value} {sens.unit}"
             if self._attr[sens.name] != newval:
                 update = True
                 self._attr[sens.name] = newval
@@ -231,4 +231,4 @@ class SMAsensor(Entity):
     @property
     def unique_id(self):
         """Return a unique identifier for this sensor."""
-        return "sma-{}-{}".format(self._sensor.key, self._sensor.name)
+        return f"sma-{self._sensor.key}-{self._sensor.name}"
diff --git a/homeassistant/components/smappee/sensor.py b/homeassistant/components/smappee/sensor.py
index cdbd1d18c299..28abf759d098 100644
--- a/homeassistant/components/smappee/sensor.py
+++ b/homeassistant/components/smappee/sensor.py
@@ -139,7 +139,7 @@ class SmappeeSensor(Entity):
         else:
             location_name = "Local"
 
-        return "{} {} {}".format(SENSOR_PREFIX, location_name, self._name)
+        return f"{SENSOR_PREFIX} {location_name} {self._name}"
 
     @property
     def icon(self):
diff --git a/homeassistant/components/smartthings/binary_sensor.py b/homeassistant/components/smartthings/binary_sensor.py
index 1ddbee6b827c..1e90709fc82c 100644
--- a/homeassistant/components/smartthings/binary_sensor.py
+++ b/homeassistant/components/smartthings/binary_sensor.py
@@ -66,12 +66,12 @@ class SmartThingsBinarySensor(SmartThingsEntity, BinarySensorDevice):
     @property
     def name(self) -> str:
         """Return the name of the binary sensor."""
-        return "{} {}".format(self._device.label, self._attribute)
+        return f"{self._device.label} {self._attribute}"
 
     @property
     def unique_id(self) -> str:
         """Return a unique ID."""
-        return "{}.{}".format(self._device.device_id, self._attribute)
+        return f"{self._device.device_id}.{self._attribute}"
 
     @property
     def is_on(self):
diff --git a/homeassistant/components/smartthings/sensor.py b/homeassistant/components/smartthings/sensor.py
index 423c141e4dab..3a6f9167054a 100644
--- a/homeassistant/components/smartthings/sensor.py
+++ b/homeassistant/components/smartthings/sensor.py
@@ -283,12 +283,12 @@ class SmartThingsSensor(SmartThingsEntity):
     @property
     def name(self) -> str:
         """Return the name of the binary sensor."""
-        return "{} {}".format(self._device.label, self._name)
+        return f"{self._device.label} {self._name}"
 
     @property
     def unique_id(self) -> str:
         """Return a unique ID."""
-        return "{}.{}".format(self._device.device_id, self._attribute)
+        return f"{self._device.device_id}.{self._attribute}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/smartthings/smartapp.py b/homeassistant/components/smartthings/smartapp.py
index b64ba690d41d..d205c1d245cb 100644
--- a/homeassistant/components/smartthings/smartapp.py
+++ b/homeassistant/components/smartthings/smartapp.py
@@ -112,7 +112,7 @@ def _get_app_template(hass: HomeAssistantType):
     cloudhook_url = hass.data[DOMAIN][CONF_CLOUDHOOK_URL]
     if cloudhook_url is not None:
         endpoint = "via Nabu Casa"
-    description = "{} {}".format(hass.config.location_name, endpoint)
+    description = f"{hass.config.location_name} {endpoint}"
 
     return {
         "app_name": APP_NAME_PREFIX + str(uuid4()),
diff --git a/homeassistant/components/smarty/binary_sensor.py b/homeassistant/components/smarty/binary_sensor.py
index 2d79700db785..8723f0248d34 100644
--- a/homeassistant/components/smarty/binary_sensor.py
+++ b/homeassistant/components/smarty/binary_sensor.py
@@ -69,9 +69,7 @@ class BoostSensor(SmartyBinarySensor):
 
     def __init__(self, name, smarty):
         """Alarm Sensor Init."""
-        super().__init__(
-            name="{} Boost State".format(name), device_class=None, smarty=smarty
-        )
+        super().__init__(name=f"{name} Boost State", device_class=None, smarty=smarty)
 
     def update(self) -> None:
         """Update state."""
@@ -84,9 +82,7 @@ class AlarmSensor(SmartyBinarySensor):
 
     def __init__(self, name, smarty):
         """Alarm Sensor Init."""
-        super().__init__(
-            name="{} Alarm".format(name), device_class="problem", smarty=smarty
-        )
+        super().__init__(name=f"{name} Alarm", device_class="problem", smarty=smarty)
 
     def update(self) -> None:
         """Update state."""
@@ -99,9 +95,7 @@ class WarningSensor(SmartyBinarySensor):
 
     def __init__(self, name, smarty):
         """Warning Sensor Init."""
-        super().__init__(
-            name="{} Warning".format(name), device_class="problem", smarty=smarty
-        )
+        super().__init__(name=f"{name} Warning", device_class="problem", smarty=smarty)
 
     def update(self) -> None:
         """Update state."""
diff --git a/homeassistant/components/smarty/sensor.py b/homeassistant/components/smarty/sensor.py
index 16d910beeb5b..bf647777b528 100644
--- a/homeassistant/components/smarty/sensor.py
+++ b/homeassistant/components/smarty/sensor.py
@@ -88,7 +88,7 @@ class SupplyAirTemperatureSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Supply Air Temperature Init."""
         super().__init__(
-            name="{} Supply Air Temperature".format(name),
+            name=f"{name} Supply Air Temperature",
             device_class=DEVICE_CLASS_TEMPERATURE,
             unit_of_measurement=TEMP_CELSIUS,
             smarty=smarty,
@@ -106,7 +106,7 @@ class ExtractAirTemperatureSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Supply Air Temperature Init."""
         super().__init__(
-            name="{} Extract Air Temperature".format(name),
+            name=f"{name} Extract Air Temperature",
             device_class=DEVICE_CLASS_TEMPERATURE,
             unit_of_measurement=TEMP_CELSIUS,
             smarty=smarty,
@@ -124,7 +124,7 @@ class OutdoorAirTemperatureSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Outdoor Air Temperature Init."""
         super().__init__(
-            name="{} Outdoor Air Temperature".format(name),
+            name=f"{name} Outdoor Air Temperature",
             device_class=DEVICE_CLASS_TEMPERATURE,
             unit_of_measurement=TEMP_CELSIUS,
             smarty=smarty,
@@ -142,7 +142,7 @@ class SupplyFanSpeedSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Supply Fan Speed RPM Init."""
         super().__init__(
-            name="{} Supply Fan Speed".format(name),
+            name=f"{name} Supply Fan Speed",
             device_class=None,
             unit_of_measurement=None,
             smarty=smarty,
@@ -160,7 +160,7 @@ class ExtractFanSpeedSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Extract Fan Speed RPM Init."""
         super().__init__(
-            name="{} Extract Fan Speed".format(name),
+            name=f"{name} Extract Fan Speed",
             device_class=None,
             unit_of_measurement=None,
             smarty=smarty,
@@ -178,7 +178,7 @@ class FilterDaysLeftSensor(SmartySensor):
     def __init__(self, name, smarty):
         """Filter Days Left Init."""
         super().__init__(
-            name="{} Filter Days Left".format(name),
+            name=f"{name} Filter Days Left",
             device_class=DEVICE_CLASS_TIMESTAMP,
             unit_of_measurement=None,
             smarty=smarty,
diff --git a/homeassistant/components/smhi/weather.py b/homeassistant/components/smhi/weather.py
index 29a8c3009445..5f6722b72a6d 100644
--- a/homeassistant/components/smhi/weather.py
+++ b/homeassistant/components/smhi/weather.py
@@ -102,7 +102,7 @@ class SmhiWeather(WeatherEntity):
     @property
     def unique_id(self) -> str:
         """Return a unique id."""
-        return "{}, {}".format(self._latitude, self._longitude)
+        return f"{self._latitude}, {self._longitude}"
 
     @Throttle(MIN_TIME_BETWEEN_UPDATES)
     async def async_update(self) -> None:
diff --git a/homeassistant/components/smtp/notify.py b/homeassistant/components/smtp/notify.py
index 7336b4577fa3..8a96865ab8db 100644
--- a/homeassistant/components/smtp/notify.py
+++ b/homeassistant/components/smtp/notify.py
@@ -182,7 +182,7 @@ class MailNotificationService(BaseNotificationService):
         msg["Subject"] = subject
         msg["To"] = ",".join(self.recipients)
         if self._sender_name:
-            msg["From"] = "{} <{}>".format(self._sender_name, self._sender)
+            msg["From"] = f"{self._sender_name} <{self._sender}>"
         else:
             msg["From"] = self._sender
         msg["X-Mailer"] = "HomeAssistant"
@@ -225,18 +225,18 @@ def _build_multipart_msg(message, images):
     msg.attach(msg_alt)
     body_txt = MIMEText(message)
     msg_alt.attach(body_txt)
-    body_text = ["<p>{}</p><br>".format(message)]
+    body_text = [f"<p>{message}</p><br>"]
 
     for atch_num, atch_name in enumerate(images):
-        cid = "image{}".format(atch_num)
-        body_text.append('<img src="cid:{}"><br>'.format(cid))
+        cid = f"image{atch_num}"
+        body_text.append(f'<img src="cid:{cid}"><br>')
         try:
             with open(atch_name, "rb") as attachment_file:
                 file_bytes = attachment_file.read()
                 try:
                     attachment = MIMEImage(file_bytes)
                     msg.attach(attachment)
-                    attachment.add_header("Content-ID", "<{}>".format(cid))
+                    attachment.add_header("Content-ID", f"<{cid}>")
                 except TypeError:
                     _LOGGER.warning(
                         "Attachment %s has an unknown MIME type. "
@@ -271,7 +271,7 @@ def _build_html_msg(text, html, images):
             with open(atch_name, "rb") as attachment_file:
                 attachment = MIMEImage(attachment_file.read(), filename=name)
             msg.attach(attachment)
-            attachment.add_header("Content-ID", "<{}>".format(name))
+            attachment.add_header("Content-ID", f"<{name}>")
         except FileNotFoundError:
             _LOGGER.warning(
                 "Attachment %s [#%s] not found. Skipping", atch_name, atch_num
diff --git a/homeassistant/components/snapcast/media_player.py b/homeassistant/components/snapcast/media_player.py
index 454201319adf..81cd6538578c 100644
--- a/homeassistant/components/snapcast/media_player.py
+++ b/homeassistant/components/snapcast/media_player.py
@@ -98,7 +98,7 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
         return
 
     # Note: Host part is needed, when using multiple snapservers
-    hpid = "{}:{}".format(host, port)
+    hpid = f"{host}:{port}"
 
     groups = [SnapcastGroupDevice(group, hpid) for group in server.groups]
     clients = [SnapcastClientDevice(client, hpid) for client in server.clients]
@@ -114,7 +114,7 @@ class SnapcastGroupDevice(MediaPlayerDevice):
         """Initialize the Snapcast group device."""
         group.set_callback(self.schedule_update_ha_state)
         self._group = group
-        self._uid = "{}{}_{}".format(GROUP_PREFIX, uid_part, self._group.identifier)
+        self._uid = f"{GROUP_PREFIX}{uid_part}_{self._group.identifier}"
 
     @property
     def state(self):
@@ -133,7 +133,7 @@ class SnapcastGroupDevice(MediaPlayerDevice):
     @property
     def name(self):
         """Return the name of the device."""
-        return "{}{}".format(GROUP_PREFIX, self._group.identifier)
+        return f"{GROUP_PREFIX}{self._group.identifier}"
 
     @property
     def source(self):
@@ -163,7 +163,7 @@ class SnapcastGroupDevice(MediaPlayerDevice):
     @property
     def device_state_attributes(self):
         """Return the state attributes."""
-        name = "{} {}".format(self._group.friendly_name, GROUP_SUFFIX)
+        name = f"{self._group.friendly_name} {GROUP_SUFFIX}"
         return {"friendly_name": name}
 
     @property
@@ -204,7 +204,7 @@ class SnapcastClientDevice(MediaPlayerDevice):
         """Initialize the Snapcast client device."""
         client.set_callback(self.schedule_update_ha_state)
         self._client = client
-        self._uid = "{}{}_{}".format(CLIENT_PREFIX, uid_part, self._client.identifier)
+        self._uid = f"{CLIENT_PREFIX}{uid_part}_{self._client.identifier}"
 
     @property
     def unique_id(self):
@@ -223,7 +223,7 @@ class SnapcastClientDevice(MediaPlayerDevice):
     @property
     def name(self):
         """Return the name of the device."""
-        return "{}{}".format(CLIENT_PREFIX, self._client.identifier)
+        return f"{CLIENT_PREFIX}{self._client.identifier}"
 
     @property
     def source(self):
@@ -260,7 +260,7 @@ class SnapcastClientDevice(MediaPlayerDevice):
     @property
     def device_state_attributes(self):
         """Return the state attributes."""
-        name = "{} {}".format(self._client.friendly_name, CLIENT_SUFFIX)
+        name = f"{self._client.friendly_name} {CLIENT_SUFFIX}"
         return {"friendly_name": name}
 
     @property
diff --git a/homeassistant/components/solaredge_local/sensor.py b/homeassistant/components/solaredge_local/sensor.py
index 80bd8e1f61ed..8586d950e39c 100644
--- a/homeassistant/components/solaredge_local/sensor.py
+++ b/homeassistant/components/solaredge_local/sensor.py
@@ -67,7 +67,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
     platform_name = config[CONF_NAME]
 
     # Create new SolarEdge object to retrieve data
-    api = SolarEdge("http://{}/".format(ip_address))
+    api = SolarEdge(f"http://{ip_address}/")
 
     # Check if api can be reached and site is active
     try:
diff --git a/homeassistant/components/solax/sensor.py b/homeassistant/components/solax/sensor.py
index 62c6a2a3a514..0c1cfcf21da3 100644
--- a/homeassistant/components/solax/sensor.py
+++ b/homeassistant/components/solax/sensor.py
@@ -35,7 +35,7 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
         idx, unit = solax.INVERTER_SENSORS[sensor]
         if unit == "C":
             unit = TEMP_CELSIUS
-        uid = "{}-{}".format(serial, idx)
+        uid = f"{serial}-{idx}"
         devices.append(Inverter(uid, serial, sensor, unit))
     endpoint.sensors = devices
     async_add_entities(devices)
@@ -97,7 +97,7 @@ class Inverter(Entity):
     @property
     def name(self):
         """Name of this inverter attribute."""
-        return "Solax {} {}".format(self.serial, self.key)
+        return f"Solax {self.serial} {self.key}"
 
     @property
     def unit_of_measurement(self):
diff --git a/homeassistant/components/somfy/config_flow.py b/homeassistant/components/somfy/config_flow.py
index 7e6645c31e2f..9f3c58c8ffba 100644
--- a/homeassistant/components/somfy/config_flow.py
+++ b/homeassistant/components/somfy/config_flow.py
@@ -73,7 +73,7 @@ class SomfyFlowHandler(config_entries.ConfigFlow):
 
         client_id = self.hass.data[DOMAIN][CLIENT_ID]
         client_secret = self.hass.data[DOMAIN][CLIENT_SECRET]
-        redirect_uri = "{}{}".format(self.hass.config.api.base_url, AUTH_CALLBACK_PATH)
+        redirect_uri = f"{self.hass.config.api.base_url}{AUTH_CALLBACK_PATH}"
         api = SomfyApi(client_id, client_secret, redirect_uri)
 
         self.hass.http.register_view(SomfyAuthCallbackView())
@@ -95,7 +95,7 @@ class SomfyFlowHandler(config_entries.ConfigFlow):
         code = self.code
         from pymfy.api.somfy_api import SomfyApi
 
-        redirect_uri = "{}{}".format(self.hass.config.api.base_url, AUTH_CALLBACK_PATH)
+        redirect_uri = f"{self.hass.config.api.base_url}{AUTH_CALLBACK_PATH}"
         api = SomfyApi(client_id, client_secret, redirect_uri)
         token = await self.hass.async_add_executor_job(api.request_token, None, code)
         _LOGGER.info("Successfully authenticated Somfy")
diff --git a/homeassistant/components/sonos/media_player.py b/homeassistant/components/sonos/media_player.py
index 70461ad15d2f..41472413a077 100644
--- a/homeassistant/components/sonos/media_player.py
+++ b/homeassistant/components/sonos/media_player.py
@@ -606,7 +606,7 @@ class SonosEntity(MediaPlayerDevice):
             #   media_artist = "Station - Artist - Title"
             # detect this case and trim from the front of
             # media_artist for cosmetics
-            trim = "{title} - ".format(title=self._media_title)
+            trim = f"{self._media_title} - "
             chars = min(len(self._media_artist), len(trim))
 
             if self._media_artist[:chars].upper() == trim[:chars].upper():
diff --git a/homeassistant/components/speedtestdotnet/const.py b/homeassistant/components/speedtestdotnet/const.py
index 90a89fcda2c6..69aadb7ac6c8 100644
--- a/homeassistant/components/speedtestdotnet/const.py
+++ b/homeassistant/components/speedtestdotnet/const.py
@@ -1,7 +1,7 @@
 """Consts used by Speedtest.net."""
 
 DOMAIN = "speedtestdotnet"
-DATA_UPDATED = "{}_data_updated".format(DOMAIN)
+DATA_UPDATED = f"{DOMAIN}_data_updated"
 
 SENSOR_TYPES = {
     "ping": ["Ping", "ms"],
diff --git a/homeassistant/components/spotcrime/sensor.py b/homeassistant/components/spotcrime/sensor.py
index 4498fd47e694..fc3a7592af31 100644
--- a/homeassistant/components/spotcrime/sensor.py
+++ b/homeassistant/components/spotcrime/sensor.py
@@ -29,7 +29,7 @@ CONF_DAYS = "days"
 DEFAULT_DAYS = 1
 NAME = "spotcrime"
 
-EVENT_INCIDENT = "{}_incident".format(NAME)
+EVENT_INCIDENT = f"{NAME}_incident"
 
 SCAN_INTERVAL = timedelta(minutes=30)
 
diff --git a/homeassistant/components/spotify/media_player.py b/homeassistant/components/spotify/media_player.py
index 74a0dc0c9c0c..31fdc09af803 100644
--- a/homeassistant/components/spotify/media_player.py
+++ b/homeassistant/components/spotify/media_player.py
@@ -99,7 +99,7 @@ def setup_platform(hass, config, add_entities, discovery_info=None):
     """Set up the Spotify platform."""
     import spotipy.oauth2
 
-    callback_url = "{}{}".format(hass.config.api.base_url, AUTH_CALLBACK_PATH)
+    callback_url = f"{hass.config.api.base_url}{AUTH_CALLBACK_PATH}"
     cache = config.get(CONF_CACHE_PATH, hass.config.path(DEFAULT_CACHE_PATH))
     oauth = spotipy.oauth2.SpotifyOAuth(
         config.get(CONF_CLIENT_ID),
diff --git a/homeassistant/components/squeezebox/media_player.py b/homeassistant/components/squeezebox/media_player.py
index 5f3a91bcf2f9..9e62e7ee0dbc 100644
--- a/homeassistant/components/squeezebox/media_player.py
+++ b/homeassistant/components/squeezebox/media_player.py
@@ -208,7 +208,7 @@ class LogitechMediaServer:
             if self._username is None
             else aiohttp.BasicAuth(self._username, self._password)
         )
-        url = "http://{}:{}/jsonrpc.js".format(self.host, self.port)
+        url = f"http://{self.host}:{self.port}/jsonrpc.js"
         data = json.dumps(
             {"id": "1", "method": "slim.request", "params": [player, command]}
         )
@@ -288,9 +288,7 @@ class SqueezeBoxDevice(MediaPlayerDevice):
     async def async_update(self):
         """Retrieve the current state of the player."""
         tags = "adKl"
-        response = await self.async_query(
-            "status", "-", "1", "tags:{tags}".format(tags=tags)
-        )
+        response = await self.async_query("status", "-", "1", f"tags:{tags}")
 
         if response is False:
             return
diff --git a/homeassistant/components/srp_energy/sensor.py b/homeassistant/components/srp_energy/sensor.py
index a9873c76afe7..f1d1787b7b48 100644
--- a/homeassistant/components/srp_energy/sensor.py
+++ b/homeassistant/components/srp_energy/sensor.py
@@ -87,7 +87,7 @@ class SrpEnergy(Entity):
         if self._state is None:
             return None
 
-        return "{0:.2f}".format(self._state)
+        return f"{self._state:.2f}"
 
     @property
     def name(self):
diff --git a/homeassistant/components/startca/sensor.py b/homeassistant/components/startca/sensor.py
index d4104dd3dcf4..5e370ed7b632 100644
--- a/homeassistant/components/startca/sensor.py
+++ b/homeassistant/components/startca/sensor.py
@@ -86,7 +86,7 @@ class StartcaSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{} {}".format(self.client_name, self._name)
+        return f"{self.client_name} {self._name}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/steam_online/sensor.py b/homeassistant/components/steam_online/sensor.py
index 924afedfbd5f..6c9c5ac6079e 100644
--- a/homeassistant/components/steam_online/sensor.py
+++ b/homeassistant/components/steam_online/sensor.py
@@ -80,7 +80,7 @@ class SteamSensor(Entity):
     @property
     def entity_id(self):
         """Return the entity ID."""
-        return "sensor.steam_{}".format(self._account)
+        return f"sensor.steam_{self._account}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/stiebel_eltron/climate.py b/homeassistant/components/stiebel_eltron/climate.py
index f2e6209d21db..ce16b10f5488 100644
--- a/homeassistant/components/stiebel_eltron/climate.py
+++ b/homeassistant/components/stiebel_eltron/climate.py
@@ -139,7 +139,7 @@ class StiebelEltron(ClimateDevice):
     @property
     def current_humidity(self):
         """Return the current humidity."""
-        return float("{0:.1f}".format(self._current_humidity))
+        return float(f"{self._current_humidity:.1f}")
 
     @property
     def hvac_modes(self):
diff --git a/homeassistant/components/stream/__init__.py b/homeassistant/components/stream/__init__.py
index 50cc1d8169d6..2ae8dd5f7140 100644
--- a/homeassistant/components/stream/__init__.py
+++ b/homeassistant/components/stream/__init__.py
@@ -217,9 +217,7 @@ async def async_handle_record_service(hass, call):
 
     # Check for file access
     if not hass.config.is_allowed_path(video_path):
-        raise HomeAssistantError(
-            "Can't write {}, no access to path!".format(video_path)
-        )
+        raise HomeAssistantError(f"Can't write {video_path}, no access to path!")
 
     # Check for active stream
     streams = hass.data[DOMAIN][ATTR_STREAMS]
@@ -231,9 +229,7 @@ async def async_handle_record_service(hass, call):
     # Add recorder
     recorder = stream.outputs.get("recorder")
     if recorder:
-        raise HomeAssistantError(
-            "Stream already recording to {}!".format(recorder.video_path)
-        )
+        raise HomeAssistantError(f"Stream already recording to {recorder.video_path}!")
 
     recorder = stream.add_provider("recorder")
     recorder.video_path = video_path
diff --git a/homeassistant/components/stream/hls.py b/homeassistant/components/stream/hls.py
index ab8779151588..c9e62f53a578 100644
--- a/homeassistant/components/stream/hls.py
+++ b/homeassistant/components/stream/hls.py
@@ -64,10 +64,7 @@ class M3U8Renderer:
     @staticmethod
     def render_preamble(track):
         """Render preamble."""
-        return [
-            "#EXT-X-VERSION:3",
-            "#EXT-X-TARGETDURATION:{}".format(track.target_duration),
-        ]
+        return ["#EXT-X-VERSION:3", f"#EXT-X-TARGETDURATION:{track.target_duration}"]
 
     @staticmethod
     def render_playlist(track, start_time):
@@ -84,7 +81,7 @@ class M3U8Renderer:
             playlist.extend(
                 [
                     "#EXTINF:{:.04f},".format(float(segment.duration)),
-                    "./segment/{}.ts".format(segment.sequence),
+                    f"./segment/{segment.sequence}.ts",
                 ]
             )
 
diff --git a/homeassistant/components/streamlabswater/binary_sensor.py b/homeassistant/components/streamlabswater/binary_sensor.py
index fd0ccb57aa60..78b2ceb40441 100644
--- a/homeassistant/components/streamlabswater/binary_sensor.py
+++ b/homeassistant/components/streamlabswater/binary_sensor.py
@@ -58,7 +58,7 @@ class StreamlabsAwayMode(BinarySensorDevice):
     @property
     def name(self):
         """Return the name for away mode."""
-        return "{} {}".format(self._location_name, NAME_AWAY_MODE)
+        return f"{self._location_name} {NAME_AWAY_MODE}"
 
     @property
     def is_on(self):
diff --git a/homeassistant/components/streamlabswater/sensor.py b/homeassistant/components/streamlabswater/sensor.py
index 69196c288f60..e7168f8ec0b5 100644
--- a/homeassistant/components/streamlabswater/sensor.py
+++ b/homeassistant/components/streamlabswater/sensor.py
@@ -79,7 +79,7 @@ class StreamLabsDailyUsage(Entity):
     @property
     def name(self):
         """Return the name for daily usage."""
-        return "{} {}".format(self._location_name, NAME_DAILY_USAGE)
+        return f"{self._location_name} {NAME_DAILY_USAGE}"
 
     @property
     def icon(self):
@@ -107,7 +107,7 @@ class StreamLabsMonthlyUsage(StreamLabsDailyUsage):
     @property
     def name(self):
         """Return the name for monthly usage."""
-        return "{} {}".format(self._location_name, NAME_MONTHLY_USAGE)
+        return f"{self._location_name} {NAME_MONTHLY_USAGE}"
 
     @property
     def state(self):
@@ -121,7 +121,7 @@ class StreamLabsYearlyUsage(StreamLabsDailyUsage):
     @property
     def name(self):
         """Return the name for yearly usage."""
-        return "{} {}".format(self._location_name, NAME_YEARLY_USAGE)
+        return f"{self._location_name} {NAME_YEARLY_USAGE}"
 
     @property
     def state(self):
diff --git a/homeassistant/components/swiss_hydrological_data/sensor.py b/homeassistant/components/swiss_hydrological_data/sensor.py
index bbac046d62ef..2d5d0e8de3f3 100644
--- a/homeassistant/components/swiss_hydrological_data/sensor.py
+++ b/homeassistant/components/swiss_hydrological_data/sensor.py
@@ -101,7 +101,7 @@ class SwissHydrologicalDataSensor(Entity):
     @property
     def unique_id(self) -> str:
         """Return a unique, friendly identifier for this entity."""
-        return "{0}_{1}".format(self._station, self._condition)
+        return f"{self._station}_{self._condition}"
 
     @property
     def unit_of_measurement(self):
diff --git a/homeassistant/components/swiss_public_transport/sensor.py b/homeassistant/components/swiss_public_transport/sensor.py
index fedcb3003b05..3cf8babf5548 100644
--- a/homeassistant/components/swiss_public_transport/sensor.py
+++ b/homeassistant/components/swiss_public_transport/sensor.py
@@ -110,7 +110,7 @@ class SwissPublicTransportSensor(Entity):
             ATTR_DEPARTURE_TIME2: self._opendata.connections[2]["departure"],
             ATTR_START: self._opendata.from_name,
             ATTR_TARGET: self._opendata.to_name,
-            ATTR_REMAINING_TIME: "{}".format(self._remaining_time),
+            ATTR_REMAINING_TIME: f"{self._remaining_time}",
             ATTR_ATTRIBUTION: ATTRIBUTION,
         }
         return attr
diff --git a/homeassistant/components/swisscom/device_tracker.py b/homeassistant/components/swisscom/device_tracker.py
index 3775854fade0..98965af15136 100644
--- a/homeassistant/components/swisscom/device_tracker.py
+++ b/homeassistant/components/swisscom/device_tracker.py
@@ -74,7 +74,7 @@ class SwisscomDeviceScanner(DeviceScanner):
 
     def get_swisscom_data(self):
         """Retrieve data from Swisscom and return parsed result."""
-        url = "http://{}/ws".format(self.host)
+        url = f"http://{self.host}/ws"
         headers = {CONTENT_TYPE: "application/x-sah-ws-4-call+json"}
         data = """
         {"service":"Devices", "method":"get",
diff --git a/homeassistant/components/switcher_kis/switch.py b/homeassistant/components/switcher_kis/switch.py
index f52935c02ec8..a758a5843472 100644
--- a/homeassistant/components/switcher_kis/switch.py
+++ b/homeassistant/components/switcher_kis/switch.py
@@ -65,7 +65,7 @@ class SwitcherControl(SwitchDevice):
     @property
     def unique_id(self) -> str:
         """Return a unique ID."""
-        return "{}-{}".format(self._device_data.device_id, self._device_data.mac_addr)
+        return f"{self._device_data.device_id}-{self._device_data.mac_addr}"
 
     @property
     def is_on(self) -> bool:
diff --git a/homeassistant/components/syncthru/sensor.py b/homeassistant/components/syncthru/sensor.py
index 0a50eec75c26..1258732223b0 100644
--- a/homeassistant/components/syncthru/sensor.py
+++ b/homeassistant/components/syncthru/sensor.py
@@ -18,12 +18,10 @@ TONER_COLORS = COLORS
 TRAYS = range(1, 6)
 OUTPUT_TRAYS = range(0, 6)
 DEFAULT_MONITORED_CONDITIONS = []
-DEFAULT_MONITORED_CONDITIONS.extend(["toner_{}".format(key) for key in TONER_COLORS])
-DEFAULT_MONITORED_CONDITIONS.extend(["drum_{}".format(key) for key in DRUM_COLORS])
-DEFAULT_MONITORED_CONDITIONS.extend(["tray_{}".format(key) for key in TRAYS])
-DEFAULT_MONITORED_CONDITIONS.extend(
-    ["output_tray_{}".format(key) for key in OUTPUT_TRAYS]
-)
+DEFAULT_MONITORED_CONDITIONS.extend([f"toner_{key}" for key in TONER_COLORS])
+DEFAULT_MONITORED_CONDITIONS.extend([f"drum_{key}" for key in DRUM_COLORS])
+DEFAULT_MONITORED_CONDITIONS.extend([f"tray_{key}" for key in TRAYS])
+DEFAULT_MONITORED_CONDITIONS.extend([f"output_tray_{key}" for key in OUTPUT_TRAYS])
 
 PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
     {
@@ -81,16 +79,16 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
     devices = [SyncThruMainSensor(printer, name)]
 
     for key in supp_toner:
-        if "toner_{}".format(key) in monitored:
+        if f"toner_{key}" in monitored:
             devices.append(SyncThruTonerSensor(printer, name, key))
     for key in supp_drum:
-        if "drum_{}".format(key) in monitored:
+        if f"drum_{key}" in monitored:
             devices.append(SyncThruDrumSensor(printer, name, key))
     for key in supp_tray:
-        if "tray_{}".format(key) in monitored:
+        if f"tray_{key}" in monitored:
             devices.append(SyncThruInputTraySensor(printer, name, key))
     for key in supp_output_tray:
-        if "output_tray_{}".format(key) in monitored:
+        if f"output_tray_{key}" in monitored:
             devices.append(SyncThruOutputTraySensor(printer, name, key))
 
     async_add_entities(devices, True)
@@ -173,10 +171,10 @@ class SyncThruTonerSensor(SyncThruSensor):
     def __init__(self, syncthru, name, color):
         """Initialize the sensor."""
         super().__init__(syncthru, name)
-        self._name = "{} Toner {}".format(name, color)
+        self._name = f"{name} Toner {color}"
         self._color = color
         self._unit_of_measurement = "%"
-        self._id_suffix = "_toner_{}".format(color)
+        self._id_suffix = f"_toner_{color}"
 
     def update(self):
         """Get the latest data from SyncThru and update the state."""
@@ -193,10 +191,10 @@ class SyncThruDrumSensor(SyncThruSensor):
     def __init__(self, syncthru, name, color):
         """Initialize the sensor."""
         super().__init__(syncthru, name)
-        self._name = "{} Drum {}".format(name, color)
+        self._name = f"{name} Drum {color}"
         self._color = color
         self._unit_of_measurement = "%"
-        self._id_suffix = "_drum_{}".format(color)
+        self._id_suffix = f"_drum_{color}"
 
     def update(self):
         """Get the latest data from SyncThru and update the state."""
@@ -213,9 +211,9 @@ class SyncThruInputTraySensor(SyncThruSensor):
     def __init__(self, syncthru, name, number):
         """Initialize the sensor."""
         super().__init__(syncthru, name)
-        self._name = "{} Tray {}".format(name, number)
+        self._name = f"{name} Tray {number}"
         self._number = number
-        self._id_suffix = "_tray_{}".format(number)
+        self._id_suffix = f"_tray_{number}"
 
     def update(self):
         """Get the latest data from SyncThru and update the state."""
@@ -234,9 +232,9 @@ class SyncThruOutputTraySensor(SyncThruSensor):
     def __init__(self, syncthru, name, number):
         """Initialize the sensor."""
         super().__init__(syncthru, name)
-        self._name = "{} Output Tray {}".format(name, number)
+        self._name = f"{name} Output Tray {number}"
         self._number = number
-        self._id_suffix = "_output_tray_{}".format(number)
+        self._id_suffix = f"_output_tray_{number}"
 
     def update(self):
         """Get the latest data from SyncThru and update the state."""
diff --git a/homeassistant/components/synologydsm/sensor.py b/homeassistant/components/synologydsm/sensor.py
index 17295f152506..e19f6ada8097 100644
--- a/homeassistant/components/synologydsm/sensor.py
+++ b/homeassistant/components/synologydsm/sensor.py
@@ -184,7 +184,7 @@ class SynoNasSensor(Entity):
     def name(self):
         """Return the name of the sensor, if any."""
         if self.monitor_device is not None:
-            return "{} ({})".format(self.var_name, self.monitor_device)
+            return f"{self.var_name} ({self.monitor_device})"
         return self.var_name
 
     @property
diff --git a/homeassistant/components/sytadin/sensor.py b/homeassistant/components/sytadin/sensor.py
index 4296f2d5b05b..b7c94933a399 100644
--- a/homeassistant/components/sytadin/sensor.py
+++ b/homeassistant/components/sytadin/sensor.py
@@ -86,7 +86,7 @@ class SytadinSensor(Entity):
     @property
     def name(self):
         """Return the name of the sensor."""
-        return "{} {}".format(self._name, self._option)
+        return f"{self._name} {self._option}"
 
     @property
     def state(self):