I'm trying to override dict class in a way that is compatible with standard dict class. How I can get access to parent dict attribute if I override __getitem__ method?
class CSJSON(dict): def __getitem__(self, Key : str): Key = Key + 'zzz' # sample of key modification for app use return(super()[Key]) Then I receive error:
'super' object is not subscriptable. If I use self[Key] then I get infinite recursive call of __getitem__.
You have to explicitly invoke __getitem__, syntax techniques like [Key] don't work on super() objects (because they don't implement __getitem__ at the class level, which is how [] is looked up when used as syntax):
class CSJSON(dict): def __getitem__(self, Key : str): Key = Key + 'zzz' # sample of key modification for app use return super().__getitem__(Key) Depending on your needs, working from collections.UserDict or abc.MutableMapping might be less painful than directly subclassing dict. There are some good discussions here about the options: 1, 2, 3
How I can get access to parent dict attribute if I override getitem method?
More experienced users here seem to prefer MutableMapping, but UserDict provides a convenient solution to this part of your question by exposing a .data dict you can manipulate as a normal dict.
