9.7 补充 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:

有时类似于Pascal中“记录（record）”或C中“结构（struct）”的数据类型很有用，它将一组已命名的数据项绑定在一起。一个空的类定义可以很好的实现这它：

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.

某一段 Python 代码需要一个特殊的抽象数据结构的话，通常可以传入一个类，事实上这模仿了该类的方法。例如，如果你有一个用于从文件对象中格式化数据的函数，你可以定义一个带有 read() 和 readline() 方法的类，以此从字符串缓冲读取数据，然后将该类的对象作为参数传入前述的函数。

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.

实例方法对象也有属性： m.im_self 是一个实例方法所属的对象，而 m.im_func 是这个方法对应的函数对象。