Function _fileobj_to_fd

Lib/selectors.py:21–43

Return a file descriptor from a file object. Parameters: fileobj -- file object or file descriptor Returns: corresponding file descriptor Raises: ValueError if the object is invalid

(fileobj)

def _fileobj_to_fd(fileobj):
    """Return a file descriptor from a file object.

    Parameters:
    fileobj -- file object or file descriptor

    Returns:
    corresponding file descriptor

    Raises:
    ValueError if the object is invalid
    """
    if isinstance(fileobj, int):
        fd = fileobj
    else:
        try:
            fd = int(fileobj.fileno())
        except (AttributeError, TypeError, ValueError):
            raise ValueError("Invalid file object: "
                             "{!r}".format(fileobj)) from None
    if fd < 0:
        raise ValueError("Invalid file descriptor: {}".format(fd))
    return fd


SelectorKey = namedtuple('SelectorKey', ['fileobj', 'fd', 'events', 'data'])