Avoid creating temporary lists (#25317)

That gives nano performance improvements as *() is slightly faster
then *[].

homeassistant/auth/__init__.py

@@ -38,8 +38,8 @@ async def auth_manager_from_config(
     store = auth_store.AuthStore(hass)
     if provider_configs:
         providers = await asyncio.gather(
-            *[auth_provider_from_config(hass, store, config)
-              for config in provider_configs])
+            *(auth_provider_from_config(hass, store, config)
+              for config in provider_configs))
     else:
         providers = ()
     # So returned auth providers are in same order as config
@@ -50,8 +50,8 @@ async def auth_manager_from_config(
 
     if module_configs:
         modules = await asyncio.gather(
-            *[auth_mfa_module_from_config(hass, config)
-              for config in module_configs])
+            *(auth_mfa_module_from_config(hass, config)
+              for config in module_configs))
     else:
         modules = ()
     # So returned auth modules are in same order as config

homeassistant/bootstrap.py

@@ -272,25 +272,25 @@ async def _async_set_up_integrations(
     debuggers = domains & DEBUGGER_INTEGRATIONS
     if debuggers:
         _LOGGER.debug("Starting up debuggers %s", debuggers)
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             async_setup_component(hass, domain, config)
-            for domain in debuggers])
+            for domain in debuggers))
         domains -= DEBUGGER_INTEGRATIONS
 
     # Resolve all dependencies of all components so we can find the logging
     # and integrations that need faster initialization.
-    resolved_domains_task = asyncio.gather(*[
+    resolved_domains_task = asyncio.gather(*(
         loader.async_component_dependencies(hass, domain)
         for domain in domains
-    ], return_exceptions=True)
+    ), return_exceptions=True)
 
     # Set up core.
     _LOGGER.debug("Setting up %s", CORE_INTEGRATIONS)
 
-    if not all(await asyncio.gather(*[
+    if not all(await asyncio.gather(*(
             async_setup_component(hass, domain, config)
             for domain in CORE_INTEGRATIONS
-    ])):
+    ))):
         _LOGGER.error("Home Assistant core failed to initialize. "
                       "Further initialization aborted")
         return
@@ -312,10 +312,10 @@ async def _async_set_up_integrations(
     if logging_domains:
         _LOGGER.info("Setting up %s", logging_domains)
 
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             async_setup_component(hass, domain, config)
             for domain in logging_domains
-        ])
+        ))
 
     # Kick off loading the registries. They don't need to be awaited.
     asyncio.gather(
@@ -324,18 +324,18 @@ async def _async_set_up_integrations(
         hass.helpers.area_registry.async_get_registry())
 
     if stage_1_domains:
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             async_setup_component(hass, domain, config)
             for domain in stage_1_domains
-        ])
+        ))
 
     # Load all integrations
     after_dependencies = {}  # type: Dict[str, Set[str]]
 
-    for int_or_exc in await asyncio.gather(*[
+    for int_or_exc in await asyncio.gather(*(
             loader.async_get_integration(hass, domain)
             for domain in stage_2_domains
-    ], return_exceptions=True):
+    ), return_exceptions=True):
         # Exceptions are handled in async_setup_component.
         if (isinstance(int_or_exc, loader.Integration) and
                 int_or_exc.after_dependencies):
@@ -360,10 +360,10 @@ async def _async_set_up_integrations(
 
         _LOGGER.debug("Setting up %s", domains_to_load)
 
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             async_setup_component(hass, domain, config)
             for domain in domains_to_load
-        ])
+        ))
 
         last_load = domains_to_load
         stage_2_domains -= domains_to_load
@@ -373,10 +373,10 @@ async def _async_set_up_integrations(
     if stage_2_domains:
         _LOGGER.debug("Final set up: %s", stage_2_domains)
 
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             async_setup_component(hass, domain, config)
             for domain in stage_2_domains
-        ])
+        ))
 
     # Wrap up startup
     await hass.async_block_till_done()

homeassistant/components/climate/reproduce_state.py

@@ -72,6 +72,6 @@ async def async_reproduce_states(hass: HomeAssistantType,
                                  states: Iterable[State],
                                  context: Optional[Context] = None) -> None:
     """Reproduce component states."""
-    await asyncio.gather(*[
+    await asyncio.gather(*(
         _async_reproduce_states(hass, state, context)
-        for state in states])
+        for state in states))

homeassistant/components/device_automation/__init__.py

@@ -57,10 +57,10 @@ async def async_get_device_automation_triggers(hass, device_id):
     for entity in entities:
         domains.add(split_entity_id(entity.entity_id)[0])
 
-    device_triggers = await asyncio.gather(*[
+    device_triggers = await asyncio.gather(*(
         _async_get_device_automation_triggers(hass, domain, device_id)
         for domain in domains
-    ])
+    ))
     for device_trigger in device_triggers:
         if device_trigger is not None:
             triggers.extend(device_trigger)

homeassistant/components/device_tracker/setup.py

@@ -95,10 +95,10 @@ async def async_extract_config(hass, config):
     """Extract device tracker config and split between legacy and modern."""
     legacy = []
 
-    for platform in await asyncio.gather(*[
+    for platform in await asyncio.gather(*(
             async_create_platform_type(hass, config, p_type, p_config)
             for p_type, p_config in config_per_platform(config, DOMAIN)
-    ]):
+    )):
         if platform is None:
             continue
 

homeassistant/components/google_assistant/smart_home.py

@@ -81,11 +81,11 @@ async def async_devices_sync(hass, data, payload):
         {'request_id': data.request_id},
         context=data.context)
 
-    devices = await asyncio.gather(*[
+    devices = await asyncio.gather(*(
         entity.sync_serialize() for entity in
         async_get_entities(hass, data.config)
         if data.config.should_expose(entity.state)
-    ])
+    ))
 
     response = {
         'agentUserId': data.config.agent_user_id or data.context.user_id,

homeassistant/components/media_player/reproduce_state.py

@@ -82,6 +82,6 @@ async def async_reproduce_states(hass: HomeAssistantType,
                                  states: Iterable[State],
                                  context: Optional[Context] = None) -> None:
     """Reproduce component states."""
-    await asyncio.gather(*[
+    await asyncio.gather(*(
         _async_reproduce_states(hass, state, context)
-        for state in states])
+        for state in states))

homeassistant/components/nextbus/sensor.py

@@ -245,10 +245,10 @@ class NextBusDepartureSensor(Entity):
         ))
 
         # Chain all predictions together
-        predictions = list(chain(*[
+        predictions = list(chain(*(
             listify(direction.get('prediction', []))
             for direction in directions
-        ]))
+        )))
 
         # Short circuit if we don't have any actual bus predictions
         if not predictions:

homeassistant/components/smartthings/__init__.py

@@ -109,8 +109,8 @@ async def async_setup_entry(hass: HomeAssistantType, entry: ConfigEntry):
                               device.label, device.device_id, exc_info=True)
                 devices.remove(device)
 
-        await asyncio.gather(*[retrieve_device_status(d)
-                               for d in devices.copy()])
+        await asyncio.gather(*(retrieve_device_status(d)
+                               for d in devices.copy()))
 
         # Sync device subscriptions
         await smartapp_sync_subscriptions(

homeassistant/components/system_health/__init__.py

@@ -65,10 +65,10 @@ async def handle_info(hass: HomeAssistantType,
         await hass.helpers.system_info.async_get_system_info()
 
     if info_callbacks:
-        for domain, domain_data in zip(info_callbacks, await asyncio.gather(*[
+        for domain, domain_data in zip(info_callbacks, await asyncio.gather(*(
                 _info_wrapper(hass, info_callback) for info_callback
                 in info_callbacks.values()
-        ])):
+        ))):
             data[domain] = domain_data
 
     connection.send_message(websocket_api.result_message(msg['id'], data))

homeassistant/helpers/service.py

@@ -189,9 +189,9 @@ async def async_get_all_descriptions(hass):
     loaded = {}
 
     if missing:
-        contents = await asyncio.gather(*[
+        contents = await asyncio.gather(*(
             _load_services_file(hass, domain) for domain in missing
-        ])
+        ))
 
         for domain, content in zip(missing, contents):
             loaded[domain] = content

homeassistant/helpers/state.py

@@ -140,10 +140,10 @@ async def async_reproduce_state(
 
     if to_call:
         # run all domains in parallel
-        await asyncio.gather(*[
+        await asyncio.gather(*(
             worker(domain, data)
             for domain, data in to_call.items()
-        ])
+        ))
 
 
 @bind_hass

homeassistant/loader.py

@@ -83,14 +83,14 @@ async def _async_get_custom_components(
     dirs = await hass.async_add_executor_job(
         get_sub_directories, custom_components.__path__)
 
-    integrations = await asyncio.gather(*[
+    integrations = await asyncio.gather(*(
         hass.async_add_executor_job(
             Integration.resolve_from_root,
             hass,
             custom_components,
             comp.name)
         for comp in dirs
-    ])
+    ))
 
     return {
         integration.domain: integration