We can extend the ABC abstractions in the numbers module to create new kinds of numbers. We might need to do this to create numeric types that fit our problem domain more precisely than the built-in numeric types. The abstractions in the numbers module need to be looked at first, because they define the existing built-in classes. Before working with new kinds of numbers, it's essential to see how the existing numbers work.
We'll digress to look at Python's operator-to-method mapping algorithm. The idea is that a binary operator has two operands; either operand can define the class that implements the operator. Python's rules for locating the relevant class are essential to decide what special methods to implement.
The essential arithmetic operators, such as +, -, *, /, //, %, and **, form the backbone of numeric operations. There are additional...
