pip/src/pip/_internal/cli/command_context.py

28 lines
760 B
Python

from contextlib import ExitStack, contextmanager
from typing import ContextManager, Iterator, TypeVar
_T = TypeVar("_T", covariant=True)
class CommandContextMixIn:
def __init__(self) -> None:
super().__init__()
self._in_main_context = False
self._main_context = ExitStack()
@contextmanager
def main_context(self) -> Iterator[None]:
assert not self._in_main_context
self._in_main_context = True
try:
with self._main_context:
yield
finally:
self._in_main_context = False
def enter_context(self, context_provider: ContextManager[_T]) -> _T:
assert self._in_main_context
return self._main_context.enter_context(context_provider)