I would phrase that as "check if any of the components of the path are links", at which point one "obvious"[*] answer is "any(x.is_symlink() for x in [*mypath.parents, mypath])".  If the path is absolute, you could use "not (mypath.resolve() == mypath)".

[*] I put that in quotes because it is only obvious once you have a non-trivial amount of experience with programming in Python.