Consider the following example:
class A: @property def x(self): return 5
So, of course calling the a = A(); a.x will retur
a = A(); a.x
In this particular case, you could define two properties, which call an underlying function:
class A: @property def x(self): return self._x(neg = False) @property def x_neg(self): return self._x(neg = True) def _x(self, neg): return 5 if not neg else -5