sets.py 文件源码

def symmetric_difference(self, other):
        """Return the symmetric difference of two sets as a new set.

        (I.e. all elements that are in exactly one of the sets.)
        """
        result = self.__class__()
        data = result._data
        value = True
        selfdata = self._data
        try:
            otherdata = other._data
        except AttributeError:
            otherdata = Set(other)._data
        for elt in ifilterfalse(otherdata.__contains__, selfdata):
            data[elt] = value
        for elt in ifilterfalse(selfdata.__contains__, otherdata):
            data[elt] = value
        return result