__init__.py — langchain Source File

Source Code

"""Helper functions for managing the LangChain API.

This module is only relevant for LangChain developers, not for users.

!!! warning

    This module and its submodules are for internal use only. Do not use them in your
    own code. We may change the API at any time with no warning.
"""

from typing import TYPE_CHECKING

from langchain_core._import_utils import import_attr

if TYPE_CHECKING:
    from langchain_core._api.beta_decorator import (
        LangChainBetaWarning,
        beta,
        suppress_langchain_beta_warning,
        surface_langchain_beta_warnings,
    )
    from langchain_core._api.deprecation import (
        LangChainDeprecationWarning,
        deprecated,
        suppress_langchain_deprecation_warning,
        surface_langchain_deprecation_warnings,
        warn_deprecated,
    )
    from langchain_core._api.path import as_import_path, get_relative_path

__all__ = (
    "LangChainBetaWarning",
    "LangChainDeprecationWarning",
    "as_import_path",
    "beta",
    "deprecated",
    "get_relative_path",
    "suppress_langchain_beta_warning",
    "suppress_langchain_deprecation_warning",
    "surface_langchain_beta_warnings",
    "surface_langchain_deprecation_warnings",
    "warn_deprecated",
)

_dynamic_imports = {
    "LangChainBetaWarning": "beta_decorator",
    "beta": "beta_decorator",
    "suppress_langchain_beta_warning": "beta_decorator",
    "surface_langchain_beta_warnings": "beta_decorator",
    "as_import_path": "path",
    "get_relative_path": "path",
    "LangChainDeprecationWarning": "deprecation",
    "deprecated": "deprecation",
    "surface_langchain_deprecation_warnings": "deprecation",
    "suppress_langchain_deprecation_warning": "deprecation",
    "warn_deprecated": "deprecation",
}


def __getattr__(attr_name: str) -> object:
    """Dynamically import and return an attribute from a submodule.

    This function enables lazy loading of API functions from submodules, reducing
    initial import time and circular dependency issues.

    Args:
        attr_name: Name of the attribute to import.

    Returns:
        The imported attribute object.

    Raises:
        AttributeError: If the attribute is not a valid dynamic import.
    """
    module_name = _dynamic_imports.get(attr_name)
    result = import_attr(attr_name, module_name, __spec__.parent)
    globals()[attr_name] = result
    return result


def __dir__() -> list[str]:
    """Return a list of available attributes for this module.

    Returns:
        List of attribute names that can be imported from this module.
    """
    return list(__all__)