def to_python(self, data):
    # no logic, pass the logic to the wrapper
    if isinstance(data, MyHexWrapper):
        return data
    else:
        return MyHexWrapper(data)

class MyHexWrapper(object):
    def __init__(self, data=None):
        # deal with all different options here
        t_data = type(data)
        if t_data is foo:
            pass
        elif t_data is bar:
            pass
        ...