Safely open path if not already open, but don't mess with pre-openend files

_maybe_open.py

from contextlib import contextmanager, ExitStack
import io

__all__ = ['maybe_open']


@contextmanager
def maybe_open(file_or_path, mode, *, **k, mode_strict=False):
    with ExitStack() as _inner_ctx:
        if isinstance(file_or_path, io.IOBase):
            file = file_or_path
        else:
            file = _inner_ctx.enter_context(open(file_or_path, mode, **k))
        if mode_strict and (file.mode != mode):
            raise TypeError(f'File is in wrong mode, {file.mode!r}')
        yield file