Python function to create a dummy classes from real classes

dummyClassFactory.py

def _dummyFactory(cls):
    """Python function to wrap a class in a dummy implementation
    
    Dummy classes created with this function will have all the
    same methods and attributes of the class they wrap, but will
    always evaluate to None. Attributes will be None in value,
    methods will be callable, but they will always return None.
    
    Parameters
    ----------
    cls : Class
        Class to be wrapped in dummy implementation
    
    Returns
    -------
    dummyClass : Class
        Wrapped input class
    """
    name = "Dummy"+cls.__name__
    
    def __getattr__(self, attr):
        if callable(getattr(cls, attr)):
            def methodWrapper(*args, **kwargs):
                 return None
            return methodWrapper
        else:
            return None
    return type(name, (cls,), {'__getattribute__': __getattr__})