In other words, classes are not usable to implement pure abstract data types. Conventionally, the first argument of methods is often called self . Any function object that is a class attribute defines a method for instances of that class. Note that this practice usually only serves to confuse the reader of a program.
Many classes like to create objects in a known initial state.
Methods may reference global names in the same way as ordinary functions. The global scope associated with a method is the module containing the class definition.