['overriding'] is in these articles:
The Python warnings
module is useful for logging messages that are not severe enough to
be considered errors.
Implementing an immutable
dictionary by overriding the modification methods of a dictionary
- A detailed look into why the Python Pickle is insecure. She also suggests that unpickling can be made safer by controlling the classes that can be created by overriding the find_class method. 
['overriding'] is in these pages: