python - pickling dict inherited class is missing internal values -

i've played around bit code , reason failure when setting 'wham' value instance of class testdict works fine long don't try pickle , unpickle it.
because if self.test missing.

traceback:

traceback (most recent call last):   file "test.py", line 30, in <module>     loads_a = loads(dumps_a)   file "test.py", line 15, in __setitem__     if self.test == false: attributeerror: 'testdict' object has no attribute 'test' 

the code:

from pickle import dumps, loads  class testdict(dict):     def __init__(self, test=false, data={}):         super().__init__(data)         self.test = test      def __getitem__(self, k):         if self.test == false:             pass         return dict.__getitem__(self, k)      def __setitem__(self, k, v):         if self.test == false:             pass         if type(v) == dict:             super().__setitem__(k, testdict(false, v))         else:             super().__setitem__(k, v)  if __name__ == '__main__':     = testdict()     a['wham'] = {'bam' : 1}     b = testdict(true)     b['wham'] = {'bam' : 2}     dumps_a = dumps(a)     dumps_b = dumps(b)      loads_a = loads(dumps_a)     loads_b = loads(dumps_b)      print(loads_a)     print(loads_b) 

the code works if not replacing __setitem__ , __getitem__ want add functionality 2 specific functions.

i've tried:

class testdict(dict):     __module__ = os.path.splitext(os.path.basename(__file__))[0] 

which sort of worked, long don't nest testdict within testdict meaning won't replace __setitem__ , __getitem__ in sub-parts of dictionary.

define __reduce__ method:

class testdict(dict):     ...      def __reduce__(self):         return type(self), (self.test, dict(self))