11.7 Odds and Ends

Sometimes it is useful to have a data type similar to the Pascal "record" or C "struct", bundling together a couple of named data items. An empty class definition will do nicely:

    class Employee:
        pass
    
    john = Employee() # Create an empty employee record
    
    # Fill the fields of the record
    john.name = 'John Doe'
    john.dept = 'computer lab'
    john.salary = 1000

A piece of Python code that expects a particular abstract data type can often be passed a class that emulates the methods of that data type instead. For instance, if you have a function that formats some data from a file object, you can define a class with methods read() and readline() that gets the data from a string buffer instead, and pass it as an argument.

Instance method objects have attributes, too: m.im_self is the object of which the method is an instance, and m.im_func is the function object corresponding to the method.