init() — langchain Function Reference

Architecture documentation for the __init__() function in chat.py from the langchain codebase.

Function python PromptManagement ChatTemplates

Entity Profile

PromptManagement→ ChatTemplates→ __init__() — langchain Function Reference

Dependency Diagram

graph TD
  c459ef0a_6231_646f_10d2_50f7028a3e0d["__init__()"]
  c5f45b6e_9126_7fa3_ba5a_e6a86d45b6d5["MessagesPlaceholder"]
  c459ef0a_6231_646f_10d2_50f7028a3e0d -->|defined in| c5f45b6e_9126_7fa3_ba5a_e6a86d45b6d5
  style c459ef0a_6231_646f_10d2_50f7028a3e0d fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/prompts/chat.py lines 144–161

    def __init__(
        self, variable_name: str, *, optional: bool = False, **kwargs: Any
    ) -> None:
        """Create a messages placeholder.

        Args:
            variable_name: Name of variable to use as messages.
            optional: Whether `format_messages` must be provided.

                If `True` format_messages can be called with no arguments and will
                return an empty list.

                If `False` then a named argument with name `variable_name` must be
                passed in, even if the value is an empty list.
        """
        # mypy can't detect the init which is defined in the parent class
        # b/c these are BaseModel classes.
        super().__init__(variable_name=variable_name, optional=optional, **kwargs)  # type: ignore[call-arg,unused-ignore]