venv/lib/python3.11/site-packages/pip/_internal/cli/command_context.py

   1 from contextlib import ExitStack, contextmanager
   2 from typing import ContextManager, Generator, TypeVar
   3
   4 _T = TypeVar("_T", covariant=True)
   5
   6
   7 class CommandContextMixIn:
   8     def __init__(self) -> None:
   9         super().__init__()
  10         self._in_main_context = False
  11         self._main_context = ExitStack()
  12
  13     @contextmanager
  14     def main_context(self) -> Generator[None, None, None]:
  15         assert not self._in_main_context
  16
  17         self._in_main_context = True
  18         try:
  19             with self._main_context:
  20                 yield
  21         finally:
  22             self._in_main_context = False
  23
  24     def enter_context(self, context_provider: ContextManager[_T]) -> _T:
  25         assert self._in_main_context
  26
  27         return self._main_context.enter_context(context_provider)