Error trying to access a parent variable from his child class - python-3.x

Question

So I have this class:
class UniversalHash(HashClass):
##################################################
def __init__(self):
super().__init__()
self.__MParamK = int(0)
self.__MParamC = int(0)
self.__MParamD = int(0)
# Override #
def FindHash(self, Key):
return (((self.__MParamK * Key) + self.__MParamC) % self.__MParamD) % self.__MParamL
def SetParamK(self, Value):
self.__MParamK = Value
def SetParamC(self, Value):
self.__MParamC = Value
def SetParamD(self, Value):
self.__MParamD = Value
And the parent class:
class HashClass:
##################################################
def __init__(self):
self.__MParamL = int(0)
def SetParamL(self, Value):
self.__MParamL = Value
def GetParamL(self):
return self.__MParamL
def FindHash(self, Key):
pass
When I try to access to the variable __MParamL (the variable created in the parent), it gives me an exception telling me that the variable is not an attribute of this class, I have searched on the web and it seems this is the correct way to write the code (maybe the overridden function is the problem?). Any help is appreciated

Answer 1

When you name an instance attribute with a leading double underscore, it will get name mangled, E.g.,
>>> class A:
... def __init__(self):
... self.x = 42
... self.__y = 42
...
>>> a = A()
>>> vars(a)
{'x': 42, '_A__y': 42}
Instead, you should just use a single underscore, E.g.,
>>> class A:
... def __init__(self):
... self.x = 42
... self._y = 42
...
>>> a = A()
>>> vars(a)
{'x': 42, '_y': 42}