sd.q = 52

 #coding:utf-8
class SD:
  def __init__(self):
    self._q = 0
  @property
  def q(self):
    print("getter")
    return self._q
  @q.setter
  def q(self, val):
    print("setter (%d)" % (val))
    self._q = val
if __name__ == "__main__":
  sd = SD()
  print(sd.q)
  sd.q = 52
  print(sd.q)

 pi@pi:~python3 test.py 
getter
0
setter (52)
getter
52

 pi@pi:~python test.py 
getter
0
52

 class SD(object):

 #
class SD:
  def __init__(self):
    self._q = 0
  @property
  def q(self):
    print("getter")
    return self._q
  @q.setter
  def new_q(self, val):
    print("setter (%d)" % (val))
    self._q = val

 #
class C(object):
    def __init__(self):
        self._x = None
    @property
    def x(self):
        """I'm the 'x' property."""
        return self._x
    @x.setter
    def x(self, value):
        self._x = value
    @x.deleter
    def x(self):
        del self._x