class DottableDict(dict):
  def __init__(self, *args, **kwargs):
    dict.__init__(self, *args, **kwargs)
    self.__dict__ = self
  def allowDotting(self, state=True):
    if state:
      self.__dict__ = self
    else:
      self.__dict__ = dict()
d = DottableDict()
d.allowDotting()
d.foo = 'bar'
print(d['foo'])
# bar
print(d.foo)
# bar
d.allowDotting(state=False)
print(d['foo'])
# bar from http://www.1sucai.cn
print(d.foo)
# AttributeError: 'DottableDict' object has no attribute 'foo'