diff --git a/libs/core/langchain_core/callbacks/file.py b/libs/core/langchain_core/callbacks/file.py
index 4912da1ec03..ac52b735c26 100644
--- a/libs/core/langchain_core/callbacks/file.py
+++ b/libs/core/langchain_core/callbacks/file.py
@@ -53,11 +53,10 @@ class FileCallbackHandler(BaseCallbackHandler):
         """
         if "name" in kwargs:
             name = kwargs["name"]
+        elif serialized:
+            name = serialized.get("name", serialized.get("id", ["<unknown>"])[-1])
         else:
-            if serialized:
-                name = serialized.get("name", serialized.get("id", ["<unknown>"])[-1])
-            else:
-                name = "<unknown>"
+            name = "<unknown>"
         print_text(
             f"\n\n\033[1m> Entering new {name} chain...\033[0m",
             end="\n",
diff --git a/libs/core/langchain_core/callbacks/manager.py b/libs/core/langchain_core/callbacks/manager.py
index 163599cb0ca..28ab582bb3e 100644
--- a/libs/core/langchain_core/callbacks/manager.py
+++ b/libs/core/langchain_core/callbacks/manager.py
@@ -364,19 +364,16 @@ async def _ahandle_event_for_handler(
             event = getattr(handler, event_name)
             if asyncio.iscoroutinefunction(event):
                 await event(*args, **kwargs)
+            elif handler.run_inline:
+                event(*args, **kwargs)
             else:
-                if handler.run_inline:
-                    event(*args, **kwargs)
-                else:
-                    await asyncio.get_event_loop().run_in_executor(
-                        None,
-                        cast(
-                            "Callable",
-                            functools.partial(
-                                copy_context().run, event, *args, **kwargs
-                            ),
-                        ),
-                    )
+                await asyncio.get_event_loop().run_in_executor(
+                    None,
+                    cast(
+                        "Callable",
+                        functools.partial(copy_context().run, event, *args, **kwargs),
+                    ),
+                )
     except NotImplementedError as e:
         if event_name == "on_chat_model_start":
             message_strings = [get_buffer_string(m) for m in args[1]]
@@ -2426,12 +2423,11 @@ def _configure(
                     for handler in callback_manager.handlers
                 ):
                     callback_manager.add_handler(var_handler, inheritable)
-            else:
-                if not any(
-                    isinstance(handler, handler_class)
-                    for handler in callback_manager.handlers
-                ):
-                    callback_manager.add_handler(var_handler, inheritable)
+            elif not any(
+                isinstance(handler, handler_class)
+                for handler in callback_manager.handlers
+            ):
+                callback_manager.add_handler(var_handler, inheritable)
     return callback_manager
 
 
diff --git a/libs/core/langchain_core/callbacks/stdout.py b/libs/core/langchain_core/callbacks/stdout.py
index ae99d3ec67b..d5359dc0805 100644
--- a/libs/core/langchain_core/callbacks/stdout.py
+++ b/libs/core/langchain_core/callbacks/stdout.py
@@ -37,11 +37,10 @@ class StdOutCallbackHandler(BaseCallbackHandler):
         """
         if "name" in kwargs:
             name = kwargs["name"]
+        elif serialized:
+            name = serialized.get("name", serialized.get("id", ["<unknown>"])[-1])
         else:
-            if serialized:
-                name = serialized.get("name", serialized.get("id", ["<unknown>"])[-1])
-            else:
-                name = "<unknown>"
+            name = "<unknown>"
         print(f"\n\n\033[1m> Entering new {name} chain...\033[0m")  # noqa: T201
 
     @override
diff --git a/libs/core/langchain_core/indexing/api.py b/libs/core/langchain_core/indexing/api.py
index c2405533582..df7dfa209e7 100644
--- a/libs/core/langchain_core/indexing/api.py
+++ b/libs/core/langchain_core/indexing/api.py
@@ -316,7 +316,7 @@ def index(
         )
         raise ValueError(msg)
 
-    if (cleanup == "incremental" or cleanup == "scoped_full") and source_id_key is None:
+    if (cleanup in {"incremental", "scoped_full"}) and source_id_key is None:
         msg = (
             "Source id key is required when cleanup mode is incremental or scoped_full."
         )
@@ -379,7 +379,7 @@ def index(
             source_id_assigner(doc) for doc in hashed_docs
         ]
 
-        if cleanup == "incremental" or cleanup == "scoped_full":
+        if cleanup in {"incremental", "scoped_full"}:
             # source ids are required.
             for source_id, hashed_doc in zip(source_ids, hashed_docs):
                 if source_id is None:
@@ -622,7 +622,7 @@ async def aindex(
         )
         raise ValueError(msg)
 
-    if (cleanup == "incremental" or cleanup == "scoped_full") and source_id_key is None:
+    if (cleanup in {"incremental", "scoped_full"}) and source_id_key is None:
         msg = (
             "Source id key is required when cleanup mode is incremental or scoped_full."
         )
@@ -667,11 +667,10 @@ async def aindex(
             # In such a case, we use the load method and convert it to an async
             # iterator.
             async_doc_iterator = _to_async_iterator(docs_source.load())
+    elif hasattr(docs_source, "__aiter__"):
+        async_doc_iterator = docs_source  # type: ignore[assignment]
     else:
-        if hasattr(docs_source, "__aiter__"):
-            async_doc_iterator = docs_source  # type: ignore[assignment]
-        else:
-            async_doc_iterator = _to_async_iterator(docs_source)
+        async_doc_iterator = _to_async_iterator(docs_source)
 
     source_id_assigner = _get_source_id_assigner(source_id_key)
 
@@ -694,7 +693,7 @@ async def aindex(
             source_id_assigner(doc) for doc in hashed_docs
         ]
 
-        if cleanup == "incremental" or cleanup == "scoped_full":
+        if cleanup in {"incremental", "scoped_full"}:
             # If the cleanup mode is incremental, source ids are required.
             for source_id, hashed_doc in zip(source_ids, hashed_docs):
                 if source_id is None:
diff --git a/libs/core/langchain_core/language_models/chat_models.py b/libs/core/langchain_core/language_models/chat_models.py
index 0a8a0022325..c5b82bfee48 100644
--- a/libs/core/langchain_core/language_models/chat_models.py
+++ b/libs/core/langchain_core/language_models/chat_models.py
@@ -955,13 +955,12 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
                     )
                 chunks.append(chunk)
             result = generate_from_stream(iter(chunks))
+        elif inspect.signature(self._generate).parameters.get("run_manager"):
+            result = self._generate(
+                messages, stop=stop, run_manager=run_manager, **kwargs
+            )
         else:
-            if inspect.signature(self._generate).parameters.get("run_manager"):
-                result = self._generate(
-                    messages, stop=stop, run_manager=run_manager, **kwargs
-                )
-            else:
-                result = self._generate(messages, stop=stop, **kwargs)
+            result = self._generate(messages, stop=stop, **kwargs)
 
         # Add response metadata to each generation
         for idx, generation in enumerate(result.generations):
@@ -1028,13 +1027,12 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
                     )
                 chunks.append(chunk)
             result = generate_from_stream(iter(chunks))
+        elif inspect.signature(self._agenerate).parameters.get("run_manager"):
+            result = await self._agenerate(
+                messages, stop=stop, run_manager=run_manager, **kwargs
+            )
         else:
-            if inspect.signature(self._agenerate).parameters.get("run_manager"):
-                result = await self._agenerate(
-                    messages, stop=stop, run_manager=run_manager, **kwargs
-                )
-            else:
-                result = await self._agenerate(messages, stop=stop, **kwargs)
+            result = await self._agenerate(messages, stop=stop, **kwargs)
 
         # Add response metadata to each generation
         for idx, generation in enumerate(result.generations):
diff --git a/libs/core/langchain_core/messages/base.py b/libs/core/langchain_core/messages/base.py
index 4baf977be48..079d90f329b 100644
--- a/libs/core/langchain_core/messages/base.py
+++ b/libs/core/langchain_core/messages/base.py
@@ -170,17 +170,16 @@ def merge_content(
             # If both are lists
             merged = merge_lists(cast("list", merged), content)  # type: ignore
         # If the first content is a list, and the second content is a string
+        # If the last element of the first content is a string
+        # Add the second content to the last element
+        elif merged and isinstance(merged[-1], str):
+            merged[-1] += content
+        # If second content is an empty string, treat as a no-op
+        elif content == "":
+            pass
         else:
-            # If the last element of the first content is a string
-            # Add the second content to the last element
-            if merged and isinstance(merged[-1], str):
-                merged[-1] += content
-            # If second content is an empty string, treat as a no-op
-            elif content == "":
-                pass
-            else:
-                # Otherwise, add the second content as a new element of the list
-                merged.append(content)
+            # Otherwise, add the second content as a new element of the list
+            merged.append(content)
     return merged
 
 
diff --git a/libs/core/langchain_core/messages/utils.py b/libs/core/langchain_core/messages/utils.py
index 3b6ab2144ff..07e9972d639 100644
--- a/libs/core/langchain_core/messages/utils.py
+++ b/libs/core/langchain_core/messages/utils.py
@@ -1030,231 +1030,222 @@ def convert_to_openai_messages(
                 content = message.content
             else:
                 content = [{"type": "text", "text": message.content}]
-        else:
-            if text_format == "string" and all(
-                isinstance(block, str) or block.get("type") == "text"
+        elif text_format == "string" and all(
+            isinstance(block, str) or block.get("type") == "text"
+            for block in message.content
+        ):
+            content = "\n".join(
+                block if isinstance(block, str) else block["text"]
                 for block in message.content
-            ):
-                content = "\n".join(
-                    block if isinstance(block, str) else block["text"]
-                    for block in message.content
-                )
-            else:
-                content = []
-                for j, block in enumerate(message.content):
-                    # OpenAI format
-                    if isinstance(block, str):
-                        content.append({"type": "text", "text": block})
-                    elif block.get("type") == "text":
-                        if missing := [k for k in ("text",) if k not in block]:
-                            err = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': 'text' "
-                                f"but is missing expected key(s) "
-                                f"{missing}. Full content block:\n\n{block}"
-                            )
-                            raise ValueError(err)
-                        content.append({"type": block["type"], "text": block["text"]})
-                    elif block.get("type") == "image_url":
-                        if missing := [k for k in ("image_url",) if k not in block]:
-                            err = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': 'image_url' "
-                                f"but is missing expected key(s) "
-                                f"{missing}. Full content block:\n\n{block}"
-                            )
-                            raise ValueError(err)
-                        content.append(
-                            {
-                                "type": "image_url",
-                                "image_url": block["image_url"],
-                            }
+            )
+        else:
+            content = []
+            for j, block in enumerate(message.content):
+                # OpenAI format
+                if isinstance(block, str):
+                    content.append({"type": "text", "text": block})
+                elif block.get("type") == "text":
+                    if missing := [k for k in ("text",) if k not in block]:
+                        err = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': 'text' "
+                            f"but is missing expected key(s) "
+                            f"{missing}. Full content block:\n\n{block}"
                         )
-                    # Anthropic and Bedrock converse format
-                    elif (block.get("type") == "image") or "image" in block:
-                        # Anthropic
-                        if source := block.get("source"):
-                            if missing := [
-                                k
-                                for k in ("media_type", "type", "data")
-                                if k not in source
-                            ]:
-                                err = (
-                                    f"Unrecognized content block at "
-                                    f"messages[{i}].content[{j}] has 'type': 'image' "
-                                    f"but 'source' is missing expected key(s) "
-                                    f"{missing}. Full content block:\n\n{block}"
-                                )
-                                raise ValueError(err)
-                            content.append(
-                                {
-                                    "type": "image_url",
-                                    "image_url": {
-                                        "url": (
-                                            f"data:{source['media_type']};"
-                                            f"{source['type']},{source['data']}"
-                                        )
-                                    },
-                                }
-                            )
-                        # Bedrock converse
-                        elif image := block.get("image"):
-                            if missing := [
-                                k for k in ("source", "format") if k not in image
-                            ]:
-                                err = (
-                                    f"Unrecognized content block at "
-                                    f"messages[{i}].content[{j}] has key 'image', "
-                                    f"but 'image' is missing expected key(s) "
-                                    f"{missing}. Full content block:\n\n{block}"
-                                )
-                                raise ValueError(err)
-                            b64_image = _bytes_to_b64_str(image["source"]["bytes"])
-                            content.append(
-                                {
-                                    "type": "image_url",
-                                    "image_url": {
-                                        "url": (
-                                            f"data:image/{image['format']};"
-                                            f"base64,{b64_image}"
-                                        )
-                                    },
-                                }
-                            )
-                        else:
+                        raise ValueError(err)
+                    content.append({"type": block["type"], "text": block["text"]})
+                elif block.get("type") == "image_url":
+                    if missing := [k for k in ("image_url",) if k not in block]:
+                        err = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': 'image_url' "
+                            f"but is missing expected key(s) "
+                            f"{missing}. Full content block:\n\n{block}"
+                        )
+                        raise ValueError(err)
+                    content.append(
+                        {
+                            "type": "image_url",
+                            "image_url": block["image_url"],
+                        }
+                    )
+                # Anthropic and Bedrock converse format
+                elif (block.get("type") == "image") or "image" in block:
+                    # Anthropic
+                    if source := block.get("source"):
+                        if missing := [
+                            k for k in ("media_type", "type", "data") if k not in source
+                        ]:
                             err = (
                                 f"Unrecognized content block at "
                                 f"messages[{i}].content[{j}] has 'type': 'image' "
-                                f"but does not have a 'source' or 'image' key. Full "
-                                f"content block:\n\n{block}"
-                            )
-                            raise ValueError(err)
-                    elif block.get("type") == "tool_use":
-                        if missing := [
-                            k for k in ("id", "name", "input") if k not in block
-                        ]:
-                            err = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': "
-                                f"'tool_use', but is missing expected key(s) "
+                                f"but 'source' is missing expected key(s) "
                                 f"{missing}. Full content block:\n\n{block}"
                             )
                             raise ValueError(err)
-                        if not any(
-                            tool_call["id"] == block["id"]
-                            for tool_call in cast("AIMessage", message).tool_calls
-                        ):
-                            oai_msg["tool_calls"] = oai_msg.get("tool_calls", [])
-                            oai_msg["tool_calls"].append(
-                                {
-                                    "type": "function",
-                                    "id": block["id"],
-                                    "function": {
-                                        "name": block["name"],
-                                        "arguments": json.dumps(block["input"]),
-                                    },
-                                }
-                            )
-                    elif block.get("type") == "tool_result":
-                        if missing := [
-                            k for k in ("content", "tool_use_id") if k not in block
-                        ]:
-                            msg = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': "
-                                f"'tool_result', but is missing expected key(s) "
-                                f"{missing}. Full content block:\n\n{block}"
-                            )
-                            raise ValueError(msg)
-                        tool_message = ToolMessage(
-                            block["content"],
-                            tool_call_id=block["tool_use_id"],
-                            status="error" if block.get("is_error") else "success",
-                        )
-                        # Recurse to make sure tool message contents are OpenAI format.
-                        tool_messages.extend(
-                            convert_to_openai_messages(
-                                [tool_message], text_format=text_format
-                            )
-                        )
-                    elif (block.get("type") == "json") or "json" in block:
-                        if "json" not in block:
-                            msg = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': 'json' "
-                                f"but does not have a 'json' key. Full "
-                                f"content block:\n\n{block}"
-                            )
-                            raise ValueError(msg)
-                        content.append(
-                            {
-                                "type": "text",
-                                "text": json.dumps(block["json"]),
-                            }
-                        )
-                    elif (
-                        block.get("type") == "guard_content"
-                    ) or "guard_content" in block:
-                        if (
-                            "guard_content" not in block
-                            or "text" not in block["guard_content"]
-                        ):
-                            msg = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': "
-                                f"'guard_content' but does not have a "
-                                f"messages[{i}].content[{j}]['guard_content']['text'] "
-                                f"key. Full content block:\n\n{block}"
-                            )
-                            raise ValueError(msg)
-                        text = block["guard_content"]["text"]
-                        if isinstance(text, dict):
-                            text = text["text"]
-                        content.append({"type": "text", "text": text})
-                    # VertexAI format
-                    elif block.get("type") == "media":
-                        if missing := [
-                            k for k in ("mime_type", "data") if k not in block
-                        ]:
-                            err = (
-                                f"Unrecognized content block at "
-                                f"messages[{i}].content[{j}] has 'type': "
-                                f"'media' but does not have key(s) {missing}. Full "
-                                f"content block:\n\n{block}"
-                            )
-                            raise ValueError(err)
-                        if "image" not in block["mime_type"]:
-                            err = (
-                                f"OpenAI messages can only support text and image data."
-                                f" Received content block with media of type:"
-                                f" {block['mime_type']}"
-                            )
-                            raise ValueError(err)
-                        b64_image = _bytes_to_b64_str(block["data"])
                         content.append(
                             {
                                 "type": "image_url",
                                 "image_url": {
                                     "url": (
-                                        f"data:{block['mime_type']};base64,{b64_image}"
+                                        f"data:{source['media_type']};"
+                                        f"{source['type']},{source['data']}"
+                                    )
+                                },
+                            }
+                        )
+                    # Bedrock converse
+                    elif image := block.get("image"):
+                        if missing := [
+                            k for k in ("source", "format") if k not in image
+                        ]:
+                            err = (
+                                f"Unrecognized content block at "
+                                f"messages[{i}].content[{j}] has key 'image', "
+                                f"but 'image' is missing expected key(s) "
+                                f"{missing}. Full content block:\n\n{block}"
+                            )
+                            raise ValueError(err)
+                        b64_image = _bytes_to_b64_str(image["source"]["bytes"])
+                        content.append(
+                            {
+                                "type": "image_url",
+                                "image_url": {
+                                    "url": (
+                                        f"data:image/{image['format']};"
+                                        f"base64,{b64_image}"
                                     )
                                 },
                             }
                         )
-                    elif block.get("type") == "thinking":
-                        content.append(block)
                     else:
                         err = (
                             f"Unrecognized content block at "
-                            f"messages[{i}].content[{j}] does not match OpenAI, "
-                            f"Anthropic, Bedrock Converse, or VertexAI format. Full "
+                            f"messages[{i}].content[{j}] has 'type': 'image' "
+                            f"but does not have a 'source' or 'image' key. Full "
                             f"content block:\n\n{block}"
                         )
                         raise ValueError(err)
-                if text_format == "string" and not any(
-                    block["type"] != "text" for block in content
-                ):
-                    content = "\n".join(block["text"] for block in content)
+                elif block.get("type") == "tool_use":
+                    if missing := [
+                        k for k in ("id", "name", "input") if k not in block
+                    ]:
+                        err = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': "
+                            f"'tool_use', but is missing expected key(s) "
+                            f"{missing}. Full content block:\n\n{block}"
+                        )
+                        raise ValueError(err)
+                    if not any(
+                        tool_call["id"] == block["id"]
+                        for tool_call in cast("AIMessage", message).tool_calls
+                    ):
+                        oai_msg["tool_calls"] = oai_msg.get("tool_calls", [])
+                        oai_msg["tool_calls"].append(
+                            {
+                                "type": "function",
+                                "id": block["id"],
+                                "function": {
+                                    "name": block["name"],
+                                    "arguments": json.dumps(block["input"]),
+                                },
+                            }
+                        )
+                elif block.get("type") == "tool_result":
+                    if missing := [
+                        k for k in ("content", "tool_use_id") if k not in block
+                    ]:
+                        msg = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': "
+                            f"'tool_result', but is missing expected key(s) "
+                            f"{missing}. Full content block:\n\n{block}"
+                        )
+                        raise ValueError(msg)
+                    tool_message = ToolMessage(
+                        block["content"],
+                        tool_call_id=block["tool_use_id"],
+                        status="error" if block.get("is_error") else "success",
+                    )
+                    # Recurse to make sure tool message contents are OpenAI format.
+                    tool_messages.extend(
+                        convert_to_openai_messages(
+                            [tool_message], text_format=text_format
+                        )
+                    )
+                elif (block.get("type") == "json") or "json" in block:
+                    if "json" not in block:
+                        msg = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': 'json' "
+                            f"but does not have a 'json' key. Full "
+                            f"content block:\n\n{block}"
+                        )
+                        raise ValueError(msg)
+                    content.append(
+                        {
+                            "type": "text",
+                            "text": json.dumps(block["json"]),
+                        }
+                    )
+                elif (block.get("type") == "guard_content") or "guard_content" in block:
+                    if (
+                        "guard_content" not in block
+                        or "text" not in block["guard_content"]
+                    ):
+                        msg = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': "
+                            f"'guard_content' but does not have a "
+                            f"messages[{i}].content[{j}]['guard_content']['text'] "
+                            f"key. Full content block:\n\n{block}"
+                        )
+                        raise ValueError(msg)
+                    text = block["guard_content"]["text"]
+                    if isinstance(text, dict):
+                        text = text["text"]
+                    content.append({"type": "text", "text": text})
+                # VertexAI format
+                elif block.get("type") == "media":
+                    if missing := [k for k in ("mime_type", "data") if k not in block]:
+                        err = (
+                            f"Unrecognized content block at "
+                            f"messages[{i}].content[{j}] has 'type': "
+                            f"'media' but does not have key(s) {missing}. Full "
+                            f"content block:\n\n{block}"
+                        )
+                        raise ValueError(err)
+                    if "image" not in block["mime_type"]:
+                        err = (
+                            f"OpenAI messages can only support text and image data."
+                            f" Received content block with media of type:"
+                            f" {block['mime_type']}"
+                        )
+                        raise ValueError(err)
+                    b64_image = _bytes_to_b64_str(block["data"])
+                    content.append(
+                        {
+                            "type": "image_url",
+                            "image_url": {
+                                "url": (f"data:{block['mime_type']};base64,{b64_image}")
+                            },
+                        }
+                    )
+                elif block.get("type") == "thinking":
+                    content.append(block)
+                else:
+                    err = (
+                        f"Unrecognized content block at "
+                        f"messages[{i}].content[{j}] does not match OpenAI, "
+                        f"Anthropic, Bedrock Converse, or VertexAI format. Full "
+                        f"content block:\n\n{block}"
+                    )
+                    raise ValueError(err)
+            if text_format == "string" and not any(
+                block["type"] != "text" for block in content
+            ):
+                content = "\n".join(block["text"] for block in content)
         oai_msg["content"] = content
         if message.content and not oai_msg["content"] and tool_messages:
             oai_messages.extend(tool_messages)
diff --git a/libs/core/langchain_core/output_parsers/openai_functions.py b/libs/core/langchain_core/output_parsers/openai_functions.py
index e5fa59bcb38..53d97e04c65 100644
--- a/libs/core/langchain_core/output_parsers/openai_functions.py
+++ b/libs/core/langchain_core/output_parsers/openai_functions.py
@@ -118,26 +118,23 @@ class JsonOutputFunctionsParser(BaseCumulativeTransformOutputParser[Any]):
                     }
                 except json.JSONDecodeError:
                     return None
+            elif self.args_only:
+                try:
+                    return json.loads(function_call["arguments"], strict=self.strict)
+                except (json.JSONDecodeError, TypeError) as exc:
+                    msg = f"Could not parse function call data: {exc}"
+                    raise OutputParserException(msg) from exc
             else:
-                if self.args_only:
-                    try:
-                        return json.loads(
+                try:
+                    return {
+                        **function_call,
+                        "arguments": json.loads(
                             function_call["arguments"], strict=self.strict
-                        )
-                    except (json.JSONDecodeError, TypeError) as exc:
-                        msg = f"Could not parse function call data: {exc}"
-                        raise OutputParserException(msg) from exc
-                else:
-                    try:
-                        return {
-                            **function_call,
-                            "arguments": json.loads(
-                                function_call["arguments"], strict=self.strict
-                            ),
-                        }
-                    except (json.JSONDecodeError, TypeError) as exc:
-                        msg = f"Could not parse function call data: {exc}"
-                        raise OutputParserException(msg) from exc
+                        ),
+                    }
+                except (json.JSONDecodeError, TypeError) as exc:
+                    msg = f"Could not parse function call data: {exc}"
+                    raise OutputParserException(msg) from exc
         except KeyError:
             return None
 
diff --git a/libs/core/langchain_core/prompts/string.py b/libs/core/langchain_core/prompts/string.py
index bad0d2fb699..d2a0f86c201 100644
--- a/libs/core/langchain_core/prompts/string.py
+++ b/libs/core/langchain_core/prompts/string.py
@@ -9,10 +9,9 @@ from typing import Any, Callable, Literal
 
 from pydantic import BaseModel, create_model
 
-import langchain_core.utils.mustache as mustache
 from langchain_core.prompt_values import PromptValue, StringPromptValue
 from langchain_core.prompts.base import BasePromptTemplate
-from langchain_core.utils import get_colored_text
+from langchain_core.utils import get_colored_text, mustache
 from langchain_core.utils.formatting import formatter
 from langchain_core.utils.interactive_env import is_interactive_env
 
diff --git a/libs/core/langchain_core/runnables/graph.py b/libs/core/langchain_core/runnables/graph.py
index c94cf1f8743..5b548ba4498 100644
--- a/libs/core/langchain_core/runnables/graph.py
+++ b/libs/core/langchain_core/runnables/graph.py
@@ -351,9 +351,7 @@ class Graph:
         """
         self.nodes.pop(node.id)
         self.edges = [
-            edge
-            for edge in self.edges
-            if edge.source != node.id and edge.target != node.id
+            edge for edge in self.edges if node.id not in (edge.source, edge.target)
         ]
 
     def add_edge(
diff --git a/libs/core/langchain_core/runnables/graph_mermaid.py b/libs/core/langchain_core/runnables/graph_mermaid.py
index 0cdb2d051ed..5ced166e08e 100644
--- a/libs/core/langchain_core/runnables/graph_mermaid.py
+++ b/libs/core/langchain_core/runnables/graph_mermaid.py
@@ -401,7 +401,7 @@ def _render_mermaid_using_api(
         f"?type={file_type}&bgColor={background_color}"
     )
     response = requests.get(image_url, timeout=10)
-    if response.status_code == 200:
+    if response.status_code == requests.codes.ok:
         img_bytes = response.content
         if output_file_path is not None:
             Path(output_file_path).write_bytes(response.content)
diff --git a/libs/core/langchain_core/tracers/root_listeners.py b/libs/core/langchain_core/tracers/root_listeners.py
index c8050d4b6b2..efe1a56e24d 100644
--- a/libs/core/langchain_core/tracers/root_listeners.py
+++ b/libs/core/langchain_core/tracers/root_listeners.py
@@ -79,9 +79,8 @@ class RootListenersTracer(BaseTracer):
         if run.error is None:
             if self._arg_on_end is not None:
                 call_func_with_variable_args(self._arg_on_end, run, self.config)
-        else:
-            if self._arg_on_error is not None:
-                call_func_with_variable_args(self._arg_on_error, run, self.config)
+        elif self._arg_on_error is not None:
+            call_func_with_variable_args(self._arg_on_error, run, self.config)
 
 
 class AsyncRootListenersTracer(AsyncBaseTracer):
@@ -143,8 +142,5 @@ class AsyncRootListenersTracer(AsyncBaseTracer):
         if run.error is None:
             if self._arg_on_end is not None:
                 await acall_func_with_variable_args(self._arg_on_end, run, self.config)
-        else:
-            if self._arg_on_error is not None:
-                await acall_func_with_variable_args(
-                    self._arg_on_error, run, self.config
-                )
+        elif self._arg_on_error is not None:
+            await acall_func_with_variable_args(self._arg_on_error, run, self.config)
diff --git a/libs/core/langchain_core/tracers/stdout.py b/libs/core/langchain_core/tracers/stdout.py
index 6fd47515fe2..2fe70ea325c 100644
--- a/libs/core/langchain_core/tracers/stdout.py
+++ b/libs/core/langchain_core/tracers/stdout.py
@@ -7,6 +7,8 @@ from langchain_core.tracers.base import BaseTracer
 from langchain_core.tracers.schemas import Run
 from langchain_core.utils.input import get_bolded_text, get_colored_text
 
+MILLISECONDS_IN_SECOND = 1000
+
 
 def try_json_stringify(obj: Any, fallback: str) -> str:
     """Try to stringify an object to JSON.
@@ -36,10 +38,10 @@ def elapsed(run: Any) -> str:
 
     """
     elapsed_time = run.end_time - run.start_time
-    milliseconds = elapsed_time.total_seconds() * 1000
-    if milliseconds < 1000:
-        return f"{milliseconds:.0f}ms"
-    return f"{(milliseconds / 1000):.2f}s"
+    seconds = elapsed_time.total_seconds()
+    if seconds < 1:
+        return f"{seconds * MILLISECONDS_IN_SECOND:.0f}ms"
+    return f"{seconds:.2f}s"
 
 
 class FunctionCallbackHandler(BaseTracer):
diff --git a/libs/core/langchain_core/utils/html.py b/libs/core/langchain_core/utils/html.py
index 15f39ee20ce..118f4de2abb 100644
--- a/libs/core/langchain_core/utils/html.py
+++ b/libs/core/langchain_core/utils/html.py
@@ -85,7 +85,7 @@ def extract_sub_links(
         try:
             parsed_link = urlparse(link)
             # Some may be absolute links like https://to/path
-            if parsed_link.scheme == "http" or parsed_link.scheme == "https":
+            if parsed_link.scheme in {"http", "https"}:
                 absolute_path = link
             # Some may have omitted the protocol like //to/path
             elif link.startswith("//"):
diff --git a/libs/core/langchain_core/utils/json.py b/libs/core/langchain_core/utils/json.py
index 3a08d181f35..4b12e85fe99 100644
--- a/libs/core/langchain_core/utils/json.py
+++ b/libs/core/langchain_core/utils/json.py
@@ -78,20 +78,19 @@ def parse_partial_json(s: str, *, strict: bool = False) -> Any:
                 escaped = not escaped
             else:
                 escaped = False
-        else:
-            if char == '"':
-                is_inside_string = True
-                escaped = False
-            elif char == "{":
-                stack.append("}")
-            elif char == "[":
-                stack.append("]")
-            elif char == "}" or char == "]":
-                if stack and stack[-1] == char:
-                    stack.pop()
-                else:
-                    # Mismatched closing character; the input is malformed.
-                    return None
+        elif char == '"':
+            is_inside_string = True
+            escaped = False
+        elif char == "{":
+            stack.append("}")
+        elif char == "[":
+            stack.append("]")
+        elif char in {"}", "]"}:
+            if stack and stack[-1] == char:
+                stack.pop()
+            else:
+                # Mismatched closing character; the input is malformed.
+                return None
 
         # Append the processed character to the new string.
         new_chars.append(new_char)
diff --git a/libs/core/langchain_core/utils/mustache.py b/libs/core/langchain_core/utils/mustache.py
index ff0b4923d58..402bde36ac5 100644
--- a/libs/core/langchain_core/utils/mustache.py
+++ b/libs/core/langchain_core/utils/mustache.py
@@ -459,12 +459,11 @@ def render(
         # Then we don't need to tokenize it
         # But it does need to be a generator
         tokens: Iterator[tuple[str, str]] = (token for token in template)
+    elif template in g_token_cache:
+        tokens = (token for token in g_token_cache[template])
     else:
-        if template in g_token_cache:
-            tokens = (token for token in g_token_cache[template])
-        else:
-            # Otherwise make a generator
-            tokens = tokenize(template, def_ldel, def_rdel)
+        # Otherwise make a generator
+        tokens = tokenize(template, def_ldel, def_rdel)
 
     output = ""
 
diff --git a/libs/core/pyproject.toml b/libs/core/pyproject.toml
index 3a5d1f6dd9a..98914361bf9 100644
--- a/libs/core/pyproject.toml
+++ b/libs/core/pyproject.toml
@@ -103,7 +103,7 @@ ignore = [
     "FBT001",
     "FBT002",
     "PGH003",
-    "PLR",
+    "PLR2004",
     "RUF",
     "SLF",
 ]
diff --git a/libs/core/tests/unit_tests/conftest.py b/libs/core/tests/unit_tests/conftest.py
index 2ed78a010b0..fb88b15fffd 100644
--- a/libs/core/tests/unit_tests/conftest.py
+++ b/libs/core/tests/unit_tests/conftest.py
@@ -112,11 +112,8 @@ def pytest_collection_modifyitems(
                             pytest.mark.skip(reason=f"Requires pkg: `{pkg}`")
                         )
                         break
-        else:
-            if only_extended:
-                item.add_marker(
-                    pytest.mark.skip(reason="Skipping not an extended test.")
-                )
+        elif only_extended:
+            item.add_marker(pytest.mark.skip(reason="Skipping not an extended test."))
 
 
 @pytest.fixture
diff --git a/libs/core/tests/unit_tests/tracers/test_schemas.py b/libs/core/tests/unit_tests/tracers/test_schemas.py
index 99a9c842eb2..4f86d0fe541 100644
--- a/libs/core/tests/unit_tests/tracers/test_schemas.py
+++ b/libs/core/tests/unit_tests/tracers/test_schemas.py
@@ -1,4 +1,4 @@
-import langchain_core.tracers.schemas as schemas
+from langchain_core.tracers import schemas
 from langchain_core.tracers.schemas import __all__ as schemas_all