def __init__(self, comparator_factory, descriptor=None, doc=None):
        self.descriptor = descriptor
        self.comparator_factory = comparator_factory
        self.doc = doc or (descriptor and descriptor.__doc__) or None
        util.set_creation_order(self)
Provides a method of applying a :class:`.PropComparator`
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/orm/descriptor_props.py/ComparableProperty.__init__