def difference_update(self, other):
        data = self._data
        if not isinstance(other, BaseSet):
            other = Set(other)
        if self is other:
            self.clear()
        for elt in ifilter(data.__contains__, other):
            del data[elt]

    # Python dict-like mass mutations: update, clear
Remove all elements of another set from this set.
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/sets.py/Set.difference_update