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httpcore/_async/connection_pool.py

@@ -1,7 +1,15 @@
 import ssl
 import sys
 from types import TracebackType
-from typing import AsyncIterable, AsyncIterator, Iterable, List, Optional, Type
+from typing import (
+    AsyncIterable,
+    AsyncIterator,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Type,
+)
 
 from .._backends.auto import AutoBackend
 from .._backends.base import SOCKET_OPTION, AsyncNetworkBackend
@@ -264,22 +272,22 @@ def _assign_requests_to_connections(self) -> List[AsyncConnectionInterface]:
                 continue
 
             origin = pool_request.request.url.origin
-            available_connections = [
+            available_connections_iter: Iterator[AsyncConnectionInterface] = (
                 connection
                 for connection in self._connections
                 if connection.can_handle_request(origin) and connection.is_available()
-            ]
+            )
+            available_connection = next(available_connections_iter, None)
 
             # There are three cases for how we may be able to handle the request:
             #
             # 1. There is an existing connection that can handle the request.
             # 2. We can create a new connection to handle the request.
             # 3. We can close an idle connection and then create a new connection
             #    to handle the request.
-            if available_connections:
+            if available_connection is not None:
                 # log: "reusing existing connection"
-                connection = available_connections[0]
-                pool_request.assign_to_connection(connection)
+                pool_request.assign_to_connection(available_connection)
             elif len(self._connections) < self._max_connections:
                 # log: "creating new connection"
                 connection = self.create_connection(origin)

httpcore/_sync/connection_pool.py

@@ -1,7 +1,15 @@
 import ssl
 import sys
 from types import TracebackType
-from typing import Iterable, Iterator, Iterable, List, Optional, Type
+from typing import (
+    Iterable,
+    Iterator,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Type,
+)
 
 from .._backends.sync import SyncBackend
 from .._backends.base import SOCKET_OPTION, NetworkBackend
@@ -264,22 +272,22 @@ def _assign_requests_to_connections(self) -> List[ConnectionInterface]:
                 continue
 
             origin = pool_request.request.url.origin
-            available_connections = [
+            available_connections_iter: Iterator[ConnectionInterface] = (
                 connection
                 for connection in self._connections
                 if connection.can_handle_request(origin) and connection.is_available()
-            ]
+            )
+            available_connection = next(available_connections_iter, None)
 
             # There are three cases for how we may be able to handle the request:
             #
             # 1. There is an existing connection that can handle the request.
             # 2. We can create a new connection to handle the request.
             # 3. We can close an idle connection and then create a new connection
             #    to handle the request.
-            if available_connections:
+            if available_connection is not None:
                 # log: "reusing existing connection"
-                connection = available_connections[0]
-                pool_request.assign_to_connection(connection)
+                pool_request.assign_to_connection(available_connection)
             elif len(self._connections) < self._max_connections:
                 # log: "creating new connection"
                 connection = self.create_connection(origin)