An alternative to method overloading

One prominent feature of many object-oriented programming languages is a tool called method overloading. Method overloading refers to having multiple methods with the same name that accept different sets of parameters. In statically typed languages, this is useful if we want to have a method that accepts either an integer or a string, for example. In non-object-oriented languages, we might need two functions, called add_s and add_i, to accommodate such situations. In statically typed object-oriented languages, we'd need two methods, both called add, one that accepts strings, and one that accepts integers.

In Python, we've already seen that we only need one method, which accepts any type of object. It may have to do some testing on the object type (for example, if it is a string, convert it to an integer), but only one method is required.

The type hints for a parameter that can take on multiple types...