Class EnvironmentVariableGuard

python/paddle/utils/environments.py:142–155

class EnvironmentVariableGuard(Generic[T]):
    variable: EnvironmentVariable[T]
    original_value: T

    def __init__(self, variable: EnvironmentVariable[T], value: T):
        self.variable = variable
        self.original_value = variable.get()
        self.variable.set(value)

    def __enter__(self) -> Self:
        return self

    def __exit__(self, exc_type, exc_value, traceback) -> None:
        self.variable.set(self.original_value)