using dir_fd=None in some functions

[Skaperen]

in The Python Library Reference i see this:

Output:
You can check whether or not dir_fd is supported on your platform using os.supports_dir_fd.
If it is unavailable, using it will raise a NotImplementedError.

my question is, does specifying dir_fd=None count as not using it? or must that option name really need to be absent to count as not using it?

i am creating a function the will be passed a path and could use a keyword option dir_fd. i am wondering if is is OK to default it to None and just pass its value along to os.lstat(...,dir_fd=dir_fd,...) or do i need to be more elaborate to handle these cases in a portable way, such as calling os.lstat() in two different ways.