https://youtu.be/V4_i7kr4FH4

rant_python-side-effects.py

import random
import pprint


class Transform:
    def __init__(self):
        self._translate = [0.0, 0.0, 0.0]
        self._rotate = [0.0, 0.0, 0.0]
        self._scale = [1.0, 1.0, 1.0]

    def __str__(self):
        return pprint.pformat(self.__dict__)

    def translate():
        def fget(self):
            return self._translate
        def fset(self, value):
            self._translate = list(value)
        return locals()
    translate = property(**translate())

    def rotate():
        def fget(self):
            return self._translate
        def fset(self, value):
            self._translate = list(value)
        return locals()
    rotate = property(**rotate())

    def scale():
        def fget(self):
            return self._translate
        def fset(self, value):
            self._translate = list(value)
        return locals()
    scale = property(**scale())


if __name__ == "__main__":
    xfo1 = Transform()
    xfo1.translate[0] = 100 * random.random()

    xfo2 = Transform()
    xfo2.translate = xfo1.translate
    xfo2.translate[0] += 5

    print(xfo1)
    print(xfo2)