OutputType() — langchain Function Reference

Architecture documentation for the OutputType() function in base.py from the langchain codebase.

Function python LangChainCore Runnables calls 2 called by 2

Entity Profile

LangChainCore→ Runnables→ OutputType() — langchain Function Reference

Dependency Diagram

graph TD
  9dbb01d7_59af_5975_c185_c4947c0f4e22["OutputType()"]
  4a62481c_02cb_a5de_1833_50669d5351a6["Runnable"]
  9dbb01d7_59af_5975_c185_c4947c0f4e22 -->|defined in| 4a62481c_02cb_a5de_1833_50669d5351a6
  469f1d08_001e_fe69_baa4_2d0cd44d0902["OutputType()"]
  469f1d08_001e_fe69_baa4_2d0cd44d0902 -->|calls| 9dbb01d7_59af_5975_c185_c4947c0f4e22
  0218d516_e05e_7abb_bf3e_d2bc7c61365e["OutputType()"]
  0218d516_e05e_7abb_bf3e_d2bc7c61365e -->|calls| 9dbb01d7_59af_5975_c185_c4947c0f4e22
  255c479b_b9fa_44d8_4de5_2562051e06b5["get_name()"]
  9dbb01d7_59af_5975_c185_c4947c0f4e22 -->|calls| 255c479b_b9fa_44d8_4de5_2562051e06b5
  0218d516_e05e_7abb_bf3e_d2bc7c61365e["OutputType()"]
  9dbb01d7_59af_5975_c185_c4947c0f4e22 -->|calls| 0218d516_e05e_7abb_bf3e_d2bc7c61365e
  style 9dbb01d7_59af_5975_c185_c4947c0f4e22 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/runnables/base.py lines 335–363

    def OutputType(self) -> type[Output]:  # noqa: N802
        """Output Type.

        The type of output this `Runnable` produces specified as a type annotation.

        Raises:
            TypeError: If the output type cannot be inferred.
        """
        # First loop through bases -- this will help generic
        # any pydantic models.
        for base in self.__class__.mro():
            if hasattr(base, "__pydantic_generic_metadata__"):
                metadata = base.__pydantic_generic_metadata__
                if (
                    "args" in metadata
                    and len(metadata["args"]) == _RUNNABLE_GENERIC_NUM_ARGS
                ):
                    return cast("type[Output]", metadata["args"][1])

        for cls in self.__class__.__orig_bases__:  # type: ignore[attr-defined]
            type_args = get_args(cls)
            if type_args and len(type_args) == _RUNNABLE_GENERIC_NUM_ARGS:
                return cast("type[Output]", type_args[1])

        msg = (
            f"Runnable {self.get_name()} doesn't have an inferable OutputType. "
            "Override the OutputType property to specify the output type."
        )
        raise TypeError(msg)