from importlib import metadata from langchain_core._api import warn_deprecated ## Create namespaces for pydantic v1 and v2. # This code must stay at the top of the file before other modules may # attempt to import pydantic since it adds pydantic_v1 and pydantic_v2 to sys.modules. # # This hack is done for the following reasons: # * Langchain will attempt to remain compatible with both pydantic v1 and v2 since # both dependencies and dependents may be stuck on either version of v1 or v2. # * Creating namespaces for pydantic v1 and v2 should allow us to write code that # unambiguously uses either v1 or v2 API. # * This change is easier to roll out and roll back. try: from pydantic.v1 import * # noqa: F403 except ImportError: from pydantic import * # type: ignore # noqa: F403 try: _PYDANTIC_MAJOR_VERSION: int = int(metadata.version("pydantic").split(".")[0]) except metadata.PackageNotFoundError: _PYDANTIC_MAJOR_VERSION = 0 warn_deprecated( "0.3.0", removal="1.0.0", alternative="pydantic.v1 or pydantic", message=( "As of langchain-core 0.3.0, LangChain uses pydantic v2 internally. " "The langchain.pydantic_v1 module was a " "compatibility shim for pydantic v1, and should no longer be used. " "Please update the code to import from Pydantic directly.\n\n" "For example, replace imports like: " "`from langchain.pydantic_v1 import BaseModel`\n" "with: `from pydantic import BaseModel`\n" "or the v1 compatibility namespace if you are working in a code base " "that has not been fully upgraded to pydantic 2 yet. " "\tfrom pydantic.v1 import BaseModel\n" ), )