MyCustomAsyncHandler Class — langchain Architecture

Architecture documentation for the MyCustomAsyncHandler class in test_fake_chat_model.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5["MyCustomAsyncHandler"]
  64513429_d001_87b1_5f19_cc17a3f3577b["AsyncCallbackHandler"]
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5 -->|extends| 64513429_d001_87b1_5f19_cc17a3f3577b
  06318702_96e4_1032_1475_4dde8fe1f643["test_fake_chat_model.py"]
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5 -->|defined in| 06318702_96e4_1032_1475_4dde8fe1f643
  1e39d1f4_a8c4_5aa5_8751_a000807af6ed["__init__()"]
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5 -->|method| 1e39d1f4_a8c4_5aa5_8751_a000807af6ed
  e79e9024_3d5b_d084_f335_deaf56d8c2bb["on_chat_model_start()"]
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5 -->|method| e79e9024_3d5b_d084_f335_deaf56d8c2bb
  2e077bb1_7a76_7fbc_b1df_bf6903ae16e1["on_llm_new_token()"]
  62e5cd38_3cf4_f6dc_d24f_67d0946e71d5 -->|method| 2e077bb1_7a76_7fbc_b1df_bf6903ae16e1

Relationship Graph

Source Code

libs/core/tests/unit_tests/fake/test_fake_chat_model.py lines 163–193

    class MyCustomAsyncHandler(AsyncCallbackHandler):
        def __init__(self, store: list[str]) -> None:
            self.store = store

        async def on_chat_model_start(
            self,
            serialized: dict[str, Any],
            messages: list[list[BaseMessage]],
            *,
            run_id: UUID,
            parent_run_id: UUID | None = None,
            tags: list[str] | None = None,
            metadata: dict[str, Any] | None = None,
            **kwargs: Any,
        ) -> Any:
            # Do nothing
            # Required to implement since this is an abstract method
            pass

        @override
        async def on_llm_new_token(
            self,
            token: str,
            *,
            chunk: GenerationChunk | ChatGenerationChunk | None = None,
            run_id: UUID,
            parent_run_id: UUID | None = None,
            tags: list[str] | None = None,
            **kwargs: Any,
        ) -> None:
            self.store.append(token)