input_variables: List[str]
    """A list of the names of the variables the prompt template expects."""
    output_parser: Optional[BaseOutputParser] = None
    """How to parse the output of calling an LLM on this formatted prompt."""
    partial_variables: Mapping[str, Union[str, Callable[[], str]]] = Field(
        default_factory=dict
    )
    @property
    def lc_serializable(self) -> bool:
        return True
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
[docs]    @abstractmethod
    def format_prompt(self, **kwargs: Any) -> PromptValue:
        """Create Chat Messages."""
    @root_validator()
    def validate_variable_names(cls, values: Dict) -> Dict:
        """Validate variable names do not include restricted names."""
        if "stop" in values["input_variables"]:
            raise ValueError(
                "Cannot have an input variable named 'stop', as it is used internally,"
                " please rename."
            )
        if "stop" in values["partial_variables"]:
            raise ValueError(
                "Cannot have an partial variable named 'stop', as it is used "
                "internally, please rename."
            )
        overall = set(values["input_variables"]).intersection(
            values["partial_variables"]
        )
        if overall:
            raise ValueError(
                f"Found overlapping input and partial variables: {overall}"
            )
        return values
[docs]    def partial(self, **kwargs: Union[str, Callable[[], str]]) -> BasePromptTemplate:
        """Return a partial of the prompt template."""
        prompt_dict = self.__dict__.copy()
        prompt_dict["input_variables"] = list(
rtdocs_stable/api.python.langchain.com/en/stable/_modules/langchain/prompts/base.html