_fileno.pyā¢799 B
from __future__ import annotations
from typing import IO, Callable
def get_fileno(file_like: IO[str]) -> int | None:
"""Get fileno() from a file, accounting for poorly implemented file-like objects.
Args:
file_like (IO): A file-like object.
Returns:
int | None: The result of fileno if available, or None if operation failed.
"""
fileno: Callable[[], int] | None = getattr(file_like, "fileno", None)
if fileno is not None:
try:
return fileno()
except Exception:
# `fileno` is documented as potentially raising a OSError
# Alas, from the issues, there are so many poorly implemented file-like objects,
# that `fileno()` can raise just about anything.
return None
return None