mirror of
https://github.com/hwchase17/langchain
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33 lines
1.3 KiB
Python
33 lines
1.3 KiB
Python
import typing
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from importlib import metadata
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## Create namespaces for pydantic v1 and v2.
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# This code must stay at the top of the file before other modules may
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# attempt to import pydantic since it adds pydantic_v1 and pydantic_v2 to sys.modules.
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#
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# This hack is done for the following reasons:
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# * Langchain will attempt to remain compatible with both pydantic v1 and v2 since
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# both dependencies and dependents may be stuck on either version of v1 or v2.
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# * Creating namespaces for pydantic v1 and v2 should allow us to write code that
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# unambiguously uses either v1 or v2 API.
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# * This change is easier to roll out and roll back.
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# It's currently impossible to support mypy for both pydantic v1 and v2 at once:
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# https://github.com/pydantic/pydantic/issues/6022
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#
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# In the lint environment, pydantic is currently v1.
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# When we upgrade it to pydantic v2, we'll need
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# to replace this with `from pydantic.v1 import *`.
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if typing.TYPE_CHECKING:
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from pydantic import * # noqa: F403
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else:
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try:
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from pydantic.v1 import * # noqa: F403
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except ImportError:
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from pydantic import * # noqa: F403
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try:
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_PYDANTIC_MAJOR_VERSION: int = int(metadata.version("pydantic").split(".")[0])
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except metadata.PackageNotFoundError:
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_PYDANTIC_MAJOR_VERSION = 0
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