metaclassでpropertyを使う。

気持ち悪い。

usual = UsualWayOfUse()
usual.x = 1
print usual.x

print '=' * 60

class KlassPropertyMeta(type):
  def fgetx(self):
    base = self.__base__
    if base != object:
      return base.fgetx() + self._x
    return self._x
  x = property(fgetx, None, None)

class KlassProperty(object):
  __metaclass__ = KlassPropertyMeta
  _x = 1

class DerivedKlassProperty(KlassProperty):
  _x = 2

print KlassProperty.x
print DerivedKlassProperty.x

kp = KlassProperty()
dkp = DerivedKlassProperty()
print kp
print dkp

実行結果

[nori@asama]~/Desktop/study/python/experiment% python classproperty.py
1
============================================================
1
3
<__main__.KlassProperty object at 0x2aaaaab48e50>
<__main__.DerivedKlassProperty object at 0x2aaaaab48e90>