diff --git a/libs/core/langchain_core/indexing/in_memory.py b/libs/core/langchain_core/indexing/in_memory.py
index a216d278132..be040b46105 100644
--- a/libs/core/langchain_core/indexing/in_memory.py
+++ b/libs/core/langchain_core/indexing/in_memory.py
@@ -66,13 +66,7 @@ class InMemoryDocumentIndex(DocumentIndex):
 
     def get(self, ids: Sequence[str], /, **kwargs: Any) -> list[Document]:
         """Get by ids."""
-        found_documents = []
-
-        for id_ in ids:
-            if id_ in self.store:
-                found_documents.append(self.store[id_])
-
-        return found_documents
+        return [self.store[id_] for id_ in ids if id_ in self.store]
 
     def _get_relevant_documents(
         self, query: str, *, run_manager: CallbackManagerForRetrieverRun
diff --git a/libs/core/langchain_core/messages/ai.py b/libs/core/langchain_core/messages/ai.py
index 46e14bf7578..49396c76fa6 100644
--- a/libs/core/langchain_core/messages/ai.py
+++ b/libs/core/langchain_core/messages/ai.py
@@ -217,31 +217,21 @@ class AIMessage(BaseMessage):
 
         # Ensure "type" is properly set on all tool call-like dicts.
         if tool_calls := values.get("tool_calls"):
-            updated: list = []
-            for tc in tool_calls:
-                updated.append(
-                    create_tool_call(**{k: v for k, v in tc.items() if k != "type"})
-                )
-            values["tool_calls"] = updated
+            values["tool_calls"] = [
+                create_tool_call(**{k: v for k, v in tc.items() if k != "type"})
+                for tc in tool_calls
+            ]
         if invalid_tool_calls := values.get("invalid_tool_calls"):
-            updated = []
-            for tc in invalid_tool_calls:
-                updated.append(
-                    create_invalid_tool_call(
-                        **{k: v for k, v in tc.items() if k != "type"}
-                    )
-                )
-            values["invalid_tool_calls"] = updated
+            values["invalid_tool_calls"] = [
+                create_invalid_tool_call(**{k: v for k, v in tc.items() if k != "type"})
+                for tc in invalid_tool_calls
+            ]
 
         if tool_call_chunks := values.get("tool_call_chunks"):
-            updated = []
-            for tc in tool_call_chunks:
-                updated.append(
-                    create_tool_call_chunk(
-                        **{k: v for k, v in tc.items() if k != "type"}
-                    )
-                )
-            values["tool_call_chunks"] = updated
+            values["tool_call_chunks"] = [
+                create_tool_call_chunk(**{k: v for k, v in tc.items() if k != "type"})
+                for tc in tool_call_chunks
+            ]
 
         return values
 
diff --git a/libs/core/langchain_core/runnables/base.py b/libs/core/langchain_core/runnables/base.py
index 700b1fc6161..a0e4cec0825 100644
--- a/libs/core/langchain_core/runnables/base.py
+++ b/libs/core/langchain_core/runnables/base.py
@@ -557,11 +557,11 @@ class Runnable(Generic[Input, Output], ABC):
         """Return a list of prompts used by this Runnable."""
         from langchain_core.prompts.base import BasePromptTemplate
 
-        prompts = []
-        for _, node in self.get_graph(config=config).nodes.items():
-            if isinstance(node.data, BasePromptTemplate):
-                prompts.append(node.data)
-        return prompts
+        return [
+            node.data
+            for node in self.get_graph(config=config).nodes.values()
+            if isinstance(node.data, BasePromptTemplate)
+        ]
 
     def __or__(
         self,
@@ -3183,9 +3183,13 @@ class RunnableSequence(RunnableSerializable[Input, Output]):
                         **(kwargs if stepidx == 0 else {}),
                     )
                     # If an input failed, add it to the map
-                    for i, inp in zip(remaining_idxs, inputs):
-                        if isinstance(inp, Exception):
-                            failed_inputs_map[i] = inp
+                    failed_inputs_map.update(
+                        {
+                            i: inp
+                            for i, inp in zip(remaining_idxs, inputs)
+                            if isinstance(inp, Exception)
+                        }
+                    )
                     inputs = [inp for inp in inputs if not isinstance(inp, Exception)]
                     # If all inputs have failed, stop processing
                     if len(failed_inputs_map) == len(configs):
@@ -3314,9 +3318,13 @@ class RunnableSequence(RunnableSerializable[Input, Output]):
                         **(kwargs if stepidx == 0 else {}),
                     )
                     # If an input failed, add it to the map
-                    for i, inp in zip(remaining_idxs, inputs):
-                        if isinstance(inp, Exception):
-                            failed_inputs_map[i] = inp
+                    failed_inputs_map.update(
+                        {
+                            i: inp
+                            for i, inp in zip(remaining_idxs, inputs)
+                            if isinstance(inp, Exception)
+                        }
+                    )
                     inputs = [inp for inp in inputs if not isinstance(inp, Exception)]
                     # If all inputs have failed, stop processing
                     if len(failed_inputs_map) == len(configs):
diff --git a/libs/core/langchain_core/runnables/graph.py b/libs/core/langchain_core/runnables/graph.py
index 6bec1fd1fce..9fe43940f32 100644
--- a/libs/core/langchain_core/runnables/graph.py
+++ b/libs/core/langchain_core/runnables/graph.py
@@ -697,10 +697,11 @@ def _first_node(graph: Graph, exclude: Sequence[str] = ()) -> Optional[Node]:
     When drawing the graph, this node would be the origin.
     """
     targets = {edge.target for edge in graph.edges if edge.source not in exclude}
-    found: list[Node] = []
-    for node in graph.nodes.values():
-        if node.id not in exclude and node.id not in targets:
-            found.append(node)
+    found: list[Node] = [
+        node
+        for node in graph.nodes.values()
+        if node.id not in exclude and node.id not in targets
+    ]
     return found[0] if len(found) == 1 else None
 
 
@@ -712,8 +713,9 @@ def _last_node(graph: Graph, exclude: Sequence[str] = ()) -> Optional[Node]:
     When drawing the graph, this node would be the destination.
     """
     sources = {edge.source for edge in graph.edges if edge.target not in exclude}
-    found: list[Node] = []
-    for node in graph.nodes.values():
-        if node.id not in exclude and node.id not in sources:
-            found.append(node)
+    found: list[Node] = [
+        node
+        for node in graph.nodes.values()
+        if node.id not in exclude and node.id not in sources
+    ]
     return found[0] if len(found) == 1 else None
diff --git a/libs/core/langchain_core/tracers/log_stream.py b/libs/core/langchain_core/tracers/log_stream.py
index bac4bca8cc9..56389a43b4a 100644
--- a/libs/core/langchain_core/tracers/log_stream.py
+++ b/libs/core/langchain_core/tracers/log_stream.py
@@ -674,10 +674,12 @@ async def _astream_log_implementation(
                             "value": copy.deepcopy(chunk),
                         }
                     )
-                for op in jsonpatch.JsonPatch.from_diff(
-                    prev_final_output, final_output, dumps=dumps
-                ):
-                    patches.append({**op, "path": f"/final_output{op['path']}"})
+                patches.extend(
+                    {**op, "path": f"/final_output{op['path']}"}
+                    for op in jsonpatch.JsonPatch.from_diff(
+                        prev_final_output, final_output, dumps=dumps
+                    )
+                )
                 await stream.send_stream.send(RunLogPatch(*patches))
         finally:
             await stream.send_stream.aclose()
diff --git a/libs/core/langchain_core/utils/function_calling.py b/libs/core/langchain_core/utils/function_calling.py
index 25248ab8707..f234bed5556 100644
--- a/libs/core/langchain_core/utils/function_calling.py
+++ b/libs/core/langchain_core/utils/function_calling.py
@@ -672,21 +672,21 @@ def tool_example_to_messages(
                 )
     """
     messages: list[BaseMessage] = [HumanMessage(content=input)]
-    openai_tool_calls = []
-    for tool_call in tool_calls:
-        openai_tool_calls.append(
-            {
-                "id": str(uuid.uuid4()),
-                "type": "function",
-                "function": {
-                    # The name of the function right now corresponds to the name
-                    # of the pydantic model. This is implicit in the API right now,
-                    # and will be improved over time.
-                    "name": tool_call.__class__.__name__,
-                    "arguments": tool_call.model_dump_json(),
-                },
-            }
-        )
+    openai_tool_calls = [
+        {
+            "id": str(uuid.uuid4()),
+            "type": "function",
+            "function": {
+                # The name of the function right now corresponds to the name
+                # of the pydantic model. This is implicit in the API right now,
+                # and will be improved over time.
+                "name": tool_call.__class__.__name__,
+                "arguments": tool_call.model_dump_json(),
+            },
+        }
+        for tool_call in tool_calls
+    ]
+
     messages.append(
         AIMessage(content="", additional_kwargs={"tool_calls": openai_tool_calls})
     )
diff --git a/libs/core/pyproject.toml b/libs/core/pyproject.toml
index c809db17d20..5d69524fee5 100644
--- a/libs/core/pyproject.toml
+++ b/libs/core/pyproject.toml
@@ -83,6 +83,7 @@ ignore = [
     "COM812", # Messes with the formatter
     "FA100", # Can't activate since we exclude UP007 for now
     "ISC001", # Messes with the formatter
+    "PERF203", # Rarely useful
     "PLR09", # Too many something (arg, statements, etc)
     "TC001", # Doesn't play well with Pydantic
     "TC002", # Doesn't play well with Pydantic
@@ -98,7 +99,6 @@ ignore = [
     "DTZ",
     "FBT",
     "FIX",
-    "PERF",
     "PGH",
     "PLC",
     "PLE",
diff --git a/libs/core/tests/unit_tests/prompts/test_chat.py b/libs/core/tests/unit_tests/prompts/test_chat.py
index 99c4350297b..ba82ff8c760 100644
--- a/libs/core/tests/unit_tests/prompts/test_chat.py
+++ b/libs/core/tests/unit_tests/prompts/test_chat.py
@@ -1014,13 +1014,12 @@ def test_chat_prompt_template_variable_names() -> None:
         prompt.get_input_schema()
 
     if record:
-        error_msg = []
-        for warning in record:
-            error_msg.append(
-                f"Warning type: {warning.category.__name__}, "
-                f"Warning message: {warning.message}, "
-                f"Warning location: {warning.filename}:{warning.lineno}"
-            )
+        error_msg = [
+            f"Warning type: {warning.category.__name__}, "
+            f"Warning message: {warning.message}, "
+            f"Warning location: {warning.filename}:{warning.lineno}"
+            for warning in record
+        ]
         msg = "\n".join(error_msg)
     else:
         msg = ""
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable.py b/libs/core/tests/unit_tests/runnables/test_runnable.py
index 67b8473fdc1..25c886e58b2 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable.py
@@ -3476,9 +3476,7 @@ def test_deep_stream() -> None:
 
     stream = chain.stream({"question": "What up"})
 
-    chunks = []
-    for chunk in stream:
-        chunks.append(chunk)
+    chunks = list(stream)
 
     assert len(chunks) == len("foo-lish")
     assert "".join(chunks) == "foo-lish"
@@ -3502,9 +3500,7 @@ def test_deep_stream_assign() -> None:
 
     stream = chain.stream({"question": "What up"})
 
-    chunks = []
-    for chunk in stream:
-        chunks.append(chunk)
+    chunks = list(stream)
 
     assert len(chunks) == len("foo-lish")
     assert add(chunks) == {"str": "foo-lish"}
@@ -3602,9 +3598,7 @@ async def test_deep_astream() -> None:
 
     stream = chain.astream({"question": "What up"})
 
-    chunks = []
-    async for chunk in stream:
-        chunks.append(chunk)
+    chunks = [chunk async for chunk in stream]
 
     assert len(chunks) == len("foo-lish")
     assert "".join(chunks) == "foo-lish"
@@ -3628,9 +3622,7 @@ async def test_deep_astream_assign() -> None:
 
     stream = chain.astream({"question": "What up"})
 
-    chunks = []
-    async for chunk in stream:
-        chunks.append(chunk)
+    chunks = [chunk async for chunk in stream]
 
     assert len(chunks) == len("foo-lish")
     assert add(chunks) == {"str": "foo-lish"}
@@ -3726,9 +3718,7 @@ def test_runnable_sequence_transform() -> None:
 
     stream = chain.transform(llm.stream("Hi there!"))
 
-    chunks = []
-    for chunk in stream:
-        chunks.append(chunk)
+    chunks = list(stream)
 
     assert len(chunks) == len("foo-lish")
     assert "".join(chunks) == "foo-lish"
@@ -3741,9 +3731,7 @@ async def test_runnable_sequence_atransform() -> None:
 
     stream = chain.atransform(llm.astream("Hi there!"))
 
-    chunks = []
-    async for chunk in stream:
-        chunks.append(chunk)
+    chunks = [chunk async for chunk in stream]
 
     assert len(chunks) == len("foo-lish")
     assert "".join(chunks) == "foo-lish"
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py b/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
index f4a6d258cc3..3080102f475 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable_events_v1.py
@@ -1493,12 +1493,12 @@ async def test_chain_ordering() -> None:
 
     events = []
 
-    for _ in range(10):
-        try:
+    try:
+        for _ in range(10):
             next_chunk = await iterable.__anext__()
             events.append(next_chunk)
-        except Exception:
-            break
+    except Exception:
+        pass
 
     events = _with_nulled_run_id(events)
     for event in events:
@@ -1610,12 +1610,12 @@ async def test_event_stream_with_retry() -> None:
 
     events = []
 
-    for _ in range(10):
-        try:
+    try:
+        for _ in range(10):
             next_chunk = await iterable.__anext__()
             events.append(next_chunk)
-        except Exception:
-            break
+    except Exception:
+        pass
 
     events = _with_nulled_run_id(events)
     for event in events:
diff --git a/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py b/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
index 5fd0891c6c5..b0fab483dc0 100644
--- a/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
+++ b/libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py
@@ -1453,12 +1453,12 @@ async def test_chain_ordering() -> None:
 
     events = []
 
-    for _ in range(10):
-        try:
+    try:
+        for _ in range(10):
             next_chunk = await iterable.__anext__()
             events.append(next_chunk)
-        except Exception:
-            break
+    except Exception:
+        pass
 
     events = _with_nulled_run_id(events)
     for event in events:
@@ -1570,12 +1570,12 @@ async def test_event_stream_with_retry() -> None:
 
     events = []
 
-    for _ in range(10):
-        try:
+    try:
+        for _ in range(10):
             next_chunk = await iterable.__anext__()
             events.append(next_chunk)
-        except Exception:
-            break
+    except Exception:
+        pass
 
     events = _with_nulled_run_id(events)
     for event in events: