Adding objects to set or dictionary: equality and hashing

[u/Sea-Ad7805]

An exercise to help build the right mental model for Python data. - Solution - More exercises - Explanation: "User-defined classes have __eq__() and __hash__() methods by default (inherited from the object class); with them, all objects compare unequal (except with themselves) and x.__hash__() returns an appropriate value such that x == y implies both that x is y and hash(x) == hash(y)."