few_shot.py — langchain Source File

Source Code

"""Prompt template that contains few shot examples."""

from __future__ import annotations

from typing import TYPE_CHECKING, Any, Literal

from pydantic import (
    BaseModel,
    ConfigDict,
    Field,
    model_validator,
)
from typing_extensions import override

from langchain_core.example_selectors import BaseExampleSelector
from langchain_core.messages import BaseMessage, get_buffer_string
from langchain_core.prompts.chat import BaseChatPromptTemplate
from langchain_core.prompts.message import BaseMessagePromptTemplate
from langchain_core.prompts.prompt import PromptTemplate
from langchain_core.prompts.string import (
    DEFAULT_FORMATTER_MAPPING,
    StringPromptTemplate,
    check_valid_template,
    get_template_variables,
)

if TYPE_CHECKING:
    from pathlib import Path

    from typing_extensions import Self


class _FewShotPromptTemplateMixin(BaseModel):
    """Prompt template that contains few shot examples."""

    examples: list[dict] | None = None
    """Examples to format into the prompt.

    Either this or `example_selector` should be provided.
    """

    example_selector: BaseExampleSelector | None = None
    """`ExampleSelector` to choose the examples to format into the prompt.

    Either this or `examples` should be provided.
    """

    model_config = ConfigDict(
        arbitrary_types_allowed=True,
        extra="forbid",
    )

    @model_validator(mode="before")
    @classmethod
    def check_examples_and_selector(cls, values: dict) -> Any:
        """Check that one and only one of `examples`/`example_selector` are provided.

        Args:
            values: The values to check.

// ... (417 more lines)