pre_init_validation() — langchain Function Reference

Architecture documentation for the pre_init_validation() function in prompt.py from the langchain codebase.

Function python PromptManagement ExampleSelection

Entity Profile

PromptManagement→ ExampleSelection→ pre_init_validation() — langchain Function Reference

Dependency Diagram

graph TD
  ec831a8d_7cb6_22ac_1b03_cb779e44bd3e["pre_init_validation()"]
  21bd3731_3333_8ace_7023_5dd43ed308cf["PromptTemplate"]
  ec831a8d_7cb6_22ac_1b03_cb779e44bd3e -->|defined in| 21bd3731_3333_8ace_7023_5dd43ed308cf
  style ec831a8d_7cb6_22ac_1b03_cb779e44bd3e fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/prompts/prompt.py lines 91–125

    def pre_init_validation(cls, values: dict) -> Any:
        """Check that template and input variables are consistent."""
        if values.get("template") is None:
            # Will let pydantic fail with a ValidationError if template
            # is not provided.
            return values

        # Set some default values based on the field defaults
        values.setdefault("template_format", "f-string")
        values.setdefault("partial_variables", {})

        if values.get("validate_template"):
            if values["template_format"] == "mustache":
                msg = "Mustache templates cannot be validated."
                raise ValueError(msg)

            if "input_variables" not in values:
                msg = "Input variables must be provided to validate the template."
                raise ValueError(msg)

            all_inputs = values["input_variables"] + list(values["partial_variables"])
            check_valid_template(
                values["template"], values["template_format"], all_inputs
            )

        if values["template_format"]:
            values["input_variables"] = [
                var
                for var in get_template_variables(
                    values["template"], values["template_format"]
                )
                if var not in values["partial_variables"]
            ]

        return values