Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/dns/_file_util.py: 38%

1# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license 

2 

3import contextlib 

4import os 

5from typing import IO, Any, cast 

6 

7 

8def as_filename(f: object) -> str | None: 

9 if isinstance(f, (str, os.PathLike)): 

10 return os.fsdecode(f) 

11 return None 

12 

13 

14def maybe_open( 

15 f: str | os.PathLike | IO[Any], mode: str = "r", encoding: str | None = None 

16) -> contextlib.AbstractContextManager[IO[Any]]: 

17 filename = as_filename(f) 

18 if filename is not None: 

19 return open(filename, mode, encoding=encoding) 

20 # as_filename() is not a type guard, so narrow f by hand 

21 return contextlib.nullcontext(cast(IO[Any], f))