core: Add ruff rules PYI (#29335)

See https://docs.astral.sh/ruff/rules/#flake8-pyi-pyi

---------

Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>

libs/core/langchain_core/callbacks/base.py

@@ -3,7 +3,9 @@
 from __future__ import annotations
 
 import logging
-from typing import TYPE_CHECKING, Any, Optional, TypeVar, Union
+from typing import TYPE_CHECKING, Any, Optional, Union
+
+from typing_extensions import Self
 
 if TYPE_CHECKING:
     from collections.abc import Sequence
@@ -879,9 +881,6 @@ class AsyncCallbackHandler(BaseCallbackHandler):
         """
 
 
-T = TypeVar("T", bound="BaseCallbackManager")
-
-
 class BaseCallbackManager(CallbackManagerMixin):
     """Base callback manager for LangChain."""
 
@@ -920,7 +919,7 @@ class BaseCallbackManager(CallbackManagerMixin):
         self.metadata = metadata or {}
         self.inheritable_metadata = inheritable_metadata or {}
 
-    def copy(self: T) -> T:
+    def copy(self) -> Self:
         """Copy the callback manager."""
         return self.__class__(
             handlers=self.handlers.copy(),
@@ -932,7 +931,7 @@ class BaseCallbackManager(CallbackManagerMixin):
             inheritable_metadata=self.inheritable_metadata.copy(),
         )
 
-    def merge(self: T, other: BaseCallbackManager) -> T:
+    def merge(self, other: BaseCallbackManager) -> Self:
         """Merge the callback manager with another callback manager.
 
         May be overwritten in subclasses. Primarily used internally

libs/core/langchain_core/callbacks/manager.py

@@ -22,6 +22,7 @@ from typing import (
 from uuid import UUID
 
 from langsmith.run_helpers import get_tracing_context
+from typing_extensions import Self
 
 from langchain_core.callbacks.base import (
     BaseCallbackHandler,
@@ -444,9 +445,6 @@ async def ahandle_event(
     )
 
 
-BRM = TypeVar("BRM", bound="BaseRunManager")
-
-
 class BaseRunManager(RunManagerMixin):
     """Base class for run manager (a bound callback manager)."""
 
@@ -489,7 +487,7 @@ class BaseRunManager(RunManagerMixin):
         self.inheritable_metadata = inheritable_metadata or {}
 
     @classmethod
-    def get_noop_manager(cls: type[BRM]) -> BRM:
+    def get_noop_manager(cls) -> Self:
         """Return a manager that doesn't perform any operations.
 
         Returns:

libs/core/langchain_core/language_models/chat_models.py

@@ -1258,7 +1258,7 @@ class BaseChatModel(BaseLanguageModel[BaseMessage], ABC):
             Union[typing.Dict[str, Any], type, Callable, BaseTool]  # noqa: UP006
         ],
         *,
-        tool_choice: Optional[Union[str, Literal["any"]]] = None,
+        tool_choice: Optional[Union[str]] = None,
         **kwargs: Any,
     ) -> Runnable[LanguageModelInput, BaseMessage]:
         """Bind tools to the model.

libs/core/langchain_core/prompts/chat.py

@@ -22,7 +22,7 @@ from pydantic import (
     SkipValidation,
     model_validator,
 )
-from typing_extensions import override
+from typing_extensions import Self, override
 
 from langchain_core._api import deprecated
 from langchain_core.load import Serializable
@@ -304,12 +304,12 @@ class BaseStringMessagePromptTemplate(BaseMessagePromptTemplate, ABC):
 
     @classmethod
     def from_template(
-        cls: type[MessagePromptTemplateT],
+        cls,
         template: str,
         template_format: PromptTemplateFormat = "f-string",
         partial_variables: Optional[dict[str, Any]] = None,
         **kwargs: Any,
-    ) -> MessagePromptTemplateT:
+    ) -> Self:
         """Create a class from a string template.
 
         Args:
@@ -335,11 +335,11 @@ class BaseStringMessagePromptTemplate(BaseMessagePromptTemplate, ABC):
 
     @classmethod
     def from_template_file(
-        cls: type[MessagePromptTemplateT],
+        cls,
         template_file: Union[str, Path],
         input_variables: list[str],
         **kwargs: Any,
-    ) -> MessagePromptTemplateT:
+    ) -> Self:
         """Create a class from a template file.
 
         Args:
@@ -456,11 +456,6 @@ class ChatMessagePromptTemplate(BaseStringMessagePromptTemplate):
         )
 
 
-_StringImageMessagePromptTemplateT = TypeVar(
-    "_StringImageMessagePromptTemplateT", bound="_StringImageMessagePromptTemplate"
-)
-
-
 class _TextTemplateParam(TypedDict, total=False):
     text: Union[str, dict]
 
@@ -483,13 +478,13 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
 
     @classmethod
     def from_template(
-        cls: type[_StringImageMessagePromptTemplateT],
+        cls: type[Self],
         template: Union[str, list[Union[str, _TextTemplateParam, _ImageTemplateParam]]],
         template_format: PromptTemplateFormat = "f-string",
         *,
         partial_variables: Optional[dict[str, Any]] = None,
         **kwargs: Any,
-    ) -> _StringImageMessagePromptTemplateT:
+    ) -> Self:
         """Create a class from a string template.
 
         Args:
@@ -576,11 +571,11 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
 
     @classmethod
     def from_template_file(
-        cls: type[_StringImageMessagePromptTemplateT],
+        cls: type[Self],
         template_file: Union[str, Path],
         input_variables: list[str],
         **kwargs: Any,
-    ) -> _StringImageMessagePromptTemplateT:
+    ) -> Self:
         """Create a class from a template file.
 
         Args:

libs/core/langchain_core/runnables/base.py

@@ -4200,7 +4200,7 @@ class RunnableGenerator(Runnable[Input, Output]):
         )
 
     @override
-    def __eq__(self, other: Any) -> bool:
+    def __eq__(self, other: object) -> bool:
         if isinstance(other, RunnableGenerator):
             if hasattr(self, "_transform") and hasattr(other, "_transform"):
                 return self._transform == other._transform
@@ -4582,7 +4582,7 @@ class RunnableLambda(Runnable[Input, Output]):
         return graph
 
     @override
-    def __eq__(self, other: Any) -> bool:
+    def __eq__(self, other: object) -> bool:
         if isinstance(other, RunnableLambda):
             if hasattr(self, "func") and hasattr(other, "func"):
                 return self.func == other.func
@@ -5880,22 +5880,24 @@ class RunnableBinding(RunnableBindingBase[Input, Output]):
 
 
 class _RunnableCallableSync(Protocol[Input, Output]):
-    def __call__(self, __in: Input, *, config: RunnableConfig) -> Output: ...
+    def __call__(self, _in: Input, /, *, config: RunnableConfig) -> Output: ...
 
 
 class _RunnableCallableAsync(Protocol[Input, Output]):
-    def __call__(self, __in: Input, *, config: RunnableConfig) -> Awaitable[Output]: ...
+    def __call__(
+        self, _in: Input, /, *, config: RunnableConfig
+    ) -> Awaitable[Output]: ...
 
 
 class _RunnableCallableIterator(Protocol[Input, Output]):
     def __call__(
-        self, __in: Iterator[Input], *, config: RunnableConfig
+        self, _in: Iterator[Input], /, *, config: RunnableConfig
     ) -> Iterator[Output]: ...
 
 
 class _RunnableCallableAsyncIterator(Protocol[Input, Output]):
     def __call__(
-        self, __in: AsyncIterator[Input], *, config: RunnableConfig
+        self, _in: AsyncIterator[Input], /, *, config: RunnableConfig
     ) -> AsyncIterator[Output]: ...
 
 

libs/core/langchain_core/runnables/utils.py

@@ -515,7 +515,7 @@ _T_contra = TypeVar("_T_contra", contravariant=True)
 class SupportsAdd(Protocol[_T_contra, _T_co]):
     """Protocol for objects that support addition."""
 
-    def __add__(self, __x: _T_contra) -> _T_co:
+    def __add__(self, x: _T_contra, /) -> _T_co:
         """Add the object to another object."""
 
 

libs/core/langchain_core/utils/aiter.py

@@ -88,7 +88,12 @@ class NoLock:
     async def __aenter__(self) -> None:
         """Do nothing."""
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
+    async def __aexit__(
+        self,
+        exc_type: Optional[type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> bool:
         """Exception not handled."""
         return False
 
@@ -237,7 +242,12 @@ class Tee(Generic[T]):
         """Return the tee instance."""
         return self
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
+    async def __aexit__(
+        self,
+        exc_type: Optional[type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> bool:
         """Close all child iterators."""
         await self.aclose()
         return False

libs/core/langchain_core/utils/iter.py

@@ -4,6 +4,7 @@ from collections import deque
 from collections.abc import Generator, Iterable, Iterator
 from contextlib import AbstractContextManager
 from itertools import islice
+from types import TracebackType
 from typing import (
     Any,
     Generic,
@@ -24,7 +25,12 @@ class NoLock:
     def __enter__(self) -> None:
         """Do nothing."""
 
-    def __exit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> Literal[False]:
+    def __exit__(
+        self,
+        exc_type: Optional[type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> Literal[False]:
         """Exception not handled."""
         return False
 
@@ -173,7 +179,12 @@ class Tee(Generic[T]):
         """Return Tee instance."""
         return self
 
-    def __exit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> Literal[False]:
+    def __exit__(
+        self,
+        exc_type: Optional[type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> Literal[False]:
         """Close all child iterators."""
         self.close()
         return False

libs/core/langchain_core/utils/pydantic.py

@@ -377,12 +377,7 @@ if IS_PYDANTIC_V2:
     def get_fields(model: BaseModelV1) -> dict[str, FieldInfoV1]: ...
 
     def get_fields(
-        model: Union[
+        model: Union[type[Union[BaseModelV2, BaseModelV1]], BaseModelV2, BaseModelV1],
-            BaseModelV2,
-            BaseModelV1,
-            type[BaseModelV2],
-            type[BaseModelV1],
-        ],
     ) -> Union[dict[str, FieldInfoV2], dict[str, FieldInfoV1]]:
         """Get the field names of a Pydantic model."""
         if hasattr(model, "model_fields"):
@@ -491,19 +486,21 @@ def _create_root_model_cached(
 
 @lru_cache(maxsize=256)
 def _create_model_cached(
-    __model_name: str,
+    model_name: str,
+    /,
     **field_definitions: Any,
 ) -> type[BaseModel]:
     return _create_model_base(
-        __model_name,
+        model_name,
         __config__=_SchemaConfig,
         **_remap_field_definitions(field_definitions),
     )
 
 
 def create_model(
-    __model_name: str,
+    model_name: str,
-    __module_name: Optional[str] = None,
+    module_name: Optional[str] = None,
+    /,
     **field_definitions: Any,
 ) -> type[BaseModel]:
     """Create a pydantic model with the given field definitions.
@@ -511,8 +508,8 @@ def create_model(
     Please use create_model_v2 instead of this function.
 
     Args:
-        __model_name: The name of the model.
+        model_name: The name of the model.
-        __module_name: The name of the module where the model is defined.
+        module_name: The name of the module where the model is defined.
             This is used by Pydantic to resolve any forward references.
         **field_definitions: The field definitions for the model.
 
@@ -524,8 +521,8 @@ def create_model(
         kwargs["root"] = field_definitions.pop("__root__")
 
     return create_model_v2(
-        __model_name,
+        model_name,
-        module_name=__module_name,
+        module_name=module_name,
         field_definitions=field_definitions,
         **kwargs,
     )

libs/core/langchain_core/vectorstores/base.py

@@ -36,6 +36,7 @@ from typing import (
 )
 
 from pydantic import ConfigDict, Field, model_validator
+from typing_extensions import Self
 
 from langchain_core.embeddings import Embeddings
 from langchain_core.retrievers import BaseRetriever, LangSmithRetrieverParams
@@ -818,11 +819,11 @@ class VectorStore(ABC):
 
     @classmethod
     def from_documents(
-        cls: type[VST],
+        cls,
         documents: list[Document],
         embedding: Embeddings,
         **kwargs: Any,
-    ) -> VST:
+    ) -> Self:
         """Return VectorStore initialized from documents and embeddings.
 
         Args:
@@ -848,11 +849,11 @@ class VectorStore(ABC):
 
     @classmethod
     async def afrom_documents(
-        cls: type[VST],
+        cls,
         documents: list[Document],
         embedding: Embeddings,
         **kwargs: Any,
-    ) -> VST:
+    ) -> Self:
         """Async return VectorStore initialized from documents and embeddings.
 
         Args:
@@ -903,14 +904,14 @@ class VectorStore(ABC):
 
     @classmethod
     async def afrom_texts(
-        cls: type[VST],
+        cls,
         texts: list[str],
         embedding: Embeddings,
         metadatas: Optional[list[dict]] = None,
         *,
         ids: Optional[list[str]] = None,
         **kwargs: Any,
-    ) -> VST:
+    ) -> Self:
         """Async return VectorStore initialized from texts and embeddings.
 
         Args:

libs/core/pyproject.toml

@@ -103,7 +103,6 @@ ignore = [
     "FBT002",
     "PGH003",
     "PLR",
-    "PYI",
     "RUF",
     "SLF",
 ]

libs/core/tests/unit_tests/runnables/test_runnable.py

@@ -5294,22 +5294,22 @@ async def test_ainvoke_on_returned_runnable() -> None:
     be runthroughaasync path (issue #13407).
     """
 
-    def idchain_sync(__input: dict) -> bool:
+    def idchain_sync(_input: dict, /) -> bool:
         return False
 
-    async def idchain_async(__input: dict) -> bool:
+    async def idchain_async(_input: dict, /) -> bool:
         return True
 
     idchain = RunnableLambda(func=idchain_sync, afunc=idchain_async)
 
-    def func(__input: dict) -> Runnable:
+    def func(_input: dict, /) -> Runnable:
         return idchain
 
     assert await RunnableLambda(func).ainvoke({})
 
 
 def test_invoke_stream_passthrough_assign_trace() -> None:
-    def idchain_sync(__input: dict) -> bool:
+    def idchain_sync(_input: dict, /) -> bool:
         return False
 
     chain = RunnablePassthrough.assign(urls=idchain_sync)
@@ -5329,7 +5329,7 @@ def test_invoke_stream_passthrough_assign_trace() -> None:
 
 
 async def test_ainvoke_astream_passthrough_assign_trace() -> None:
-    def idchain_sync(__input: dict) -> bool:
+    def idchain_sync(_input: dict, /) -> bool:
         return False
 
     chain = RunnablePassthrough.assign(urls=idchain_sync)

libs/core/tests/unit_tests/stubs.py

@@ -7,7 +7,7 @@ from langchain_core.messages import AIMessage, AIMessageChunk, HumanMessage
 class AnyStr(str):
     __slots__ = ()
 
-    def __eq__(self, other: Any) -> bool:
+    def __eq__(self, other: object) -> bool:
         return isinstance(other, str)
 
 

libs/core/tests/unit_tests/test_tools.py

@@ -2369,7 +2369,7 @@ def test_tool_return_output_mixin() -> None:
         def __init__(self, x: int) -> None:
             self.x = x
 
-        def __eq__(self, other: Any) -> bool:
+        def __eq__(self, other: object) -> bool:
             return isinstance(other, self.__class__) and self.x == other.x
 
     @tool

libs/core/tests/unit_tests/utils/test_function_calling.py

@@ -994,12 +994,12 @@ def test__convert_typed_dict_to_openai_function_fail(typed_dict: type) -> None:
 )
 def test_convert_union_type_py_39() -> None:
     @tool
-    def magic_function(input: int | float) -> str:  # noqa: FA102
+    def magic_function(input: int | str) -> str:  # noqa: FA102
         """Compute a magic function."""
 
     result = convert_to_openai_function(magic_function)
     assert result["parameters"]["properties"]["input"] == {
-        "anyOf": [{"type": "integer"}, {"type": "number"}]
+        "anyOf": [{"type": "integer"}, {"type": "string"}]
     }