When comparing for equality, compare floats up to
        a limited precision specified by "places".

def almost_equal(self, v2, places=7):
        """When comparing for equality, compare floats up to
        a limited precision specified by "places".
        """

        try:
            return (
                len(self) == len(v2) and
                _float_almost_equal(self.x, v2.x, places) and
                _float_almost_equal(self.y, v2.y, places) and
                _float_almost_equal(self.z, v2.z, places))
        except:
            return False