Look first here : https://docs.python.org/3/library/collections.abc.html
Share your ideas about optimizing the "None" objects.
Here are the ideas I had so far:

• __contains__ should be a simple method that directly returns False, it concerns NoneContainer, NoneCollection and NoneMapping;
• __iter__ should be a simple method that directly returns self, it concerns NoneIterable, NoneCollection and NoneMapping;
• __next__ should be a simple method that directly raises the StopIteration exception, it concerns NoneIterable, NoneCollection and NoneMapping;
• __len__ should be a simple method that directly returns 0, it concerns NoneCollection and NoneMapping;
• __getitem__ should be a simple method that directly raises the KeyError exception, it concerns NoneMapping;
• keys should be a simple method that directly returns self, it concerns NoneMapping;
• items should be a simple method that directly returns self, it concerns NoneMapping;
• values should be a simple method that directly returns self, it concerns NoneMapping;
• get should be a simple method that directly returns its default, it concerns NoneMapping.

Here are the things where the discussion is wide open:

• __eq__ I don't know yet, should it return False, or the result of is self (in this respect should we have NoneContainer is NoneIterable as is the case right now, etc.);
• __ne__ same discussion here.