Question

I have a the following class:

class Vector(object):
    def __init__(self, x=0, y=0, z=0):
        self.x = x
        self.y = y
        self.z = z

    def _getx(self):
        return self._x
    def _setx(self, value):
        self._x = float(value)
    x = property(_getx, _setx)

    def _gety(self):
        return self._y
    def _sety(self, value):
        self._y = float(value)
    y = property(_gety, _sety)

    def _getz(self):
        return self._z
    def _setz(self, value):
        self._z = float(value)
    z = property(_getz, _setz)

The three getters and setters are all identical except for the object property they are modifying (x, y, z). Is there a way that I can write one get and one set and then pass the variable to modify so that I don’t repeat myself?

Answer 1

Sure, make a custom descriptor as per the concepts clearly explained in this doc:

class JonProperty(object):
    def __init__(self, name):
        self.name = name

    def __get__(self, obj, objtype):
        return getattr(obj, self.name)

    def __set__(self, obj, val):
        setattr(obj, self.name, float(val))

and then just use it:

class Vector(object):
    def __init__(self, x=0, y=0, z=0):
        self.x = x
        self.y = y
        self.z = z
    x = JonProperty('_x')
    y = JonProperty('_y')
    z = JonProperty('_z')