In Python 3.3 threading.get_ident() has been added as a public and documented function, but there is no dummy_threading.get_ident():

    >>> import threading, dummy_threading
    >>> threading.get_ident()
    139974728402752
    >>> dummy_threading.get_ident()
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    AttributeError: 'module' object has no attribute 'get_ident'

By the way: it may be worth to check for other possible inconsistencies between avaliable interfaces of threading and dummy_threading.