[illuminati tmp]$ touch a
[illuminati tmp]$ ln -s /tmp/a b
[illuminati tmp]$ python2.7 -c 'import os; print(os.readlink("b"))'
/tmp/a
[illuminati tmp]$ mv -f a b
[illuminati tmp]$ python2.7 -c 'import os; print(os.readlink("b"))'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
OSError: [Errno 22] Invalid argument: ‘b’