Python基础部分学完之后，在进入其OOP部分前，先理解一下其装饰器这种结构，其功能可类比于Java中的面向切面编程，下面参见具体实例:

def log(f):    def fn(x):        print 'call ' + f.__name__ + '()...'        return f(x)    return fnprint '------------ 直接调  ----------- 'g = log(int)g('10010')                      # 只调不打印返回值print ''print g('10010')                # 又调又打印输出结果print '------------ 装饰器  ----------- '@logdef myabs(x):     if x < 0:        return -x    else:        return xprint myabs(-17)# 下面是错误的装饰器调用# @log# def add(x,y):#     return x + y# print add(4,8)print '----------- 修改装饰器以支持多参数 -----------'def log2(f):    def fn(*args,**kv):        print 'call ' + f.__name__ + '()...'        return f(*args,**kv)    return fn@log2def add(x,y):    return x + yprint add(4,8)print '-------------------- 带参的装饰器  ------------------------'def log3(prefix):    def log_decorator(f):        def fn(*args,**kv):            print '[%s] %s()...' % (prefix,f.__name__)            return f(*args,**kv)        return fn    return log_decoratorprint '---- 普通调用 -----'def division(x,y):    return x/ylog_decorator = log3('DEBUG')division = log_decorator(division)print division(18, 6)print '---- 装饰器调用 ----'@log3('DEBUG')def multiplication(a,b):    return a * bprint multiplication(3, 4)

　　下面针对Python类中几个常见的特殊方法重写:

class Student(object):    def __init__(self,name,score):        self.name = name        self.score = score    def __str__(self):        return '(Student: %s, %s)' % (self.name,self.score)    def __cmp__(self,s):        if self.name < s.name:            return -1        elif self.name > s.name:            return 1        else:            return 0    def __call__(self,friend):        print 'My name is %s...' % self.name        print 'My friend is %s...' % friend.name    print '------- basic info output ------------'    John = Student('John',99)Alice = Student('Alice',85)print Johnprint Aliceprint '\n------------ special called -------------'John.gender = 'male'print 'changed: ' , John # 没打印出来新属性gender，因为自定义的__str__方法中没有print John.gender        # 确实给John添加了新属性John(Alice)print '\n------------ instance sort --------------'L = [John,Alice]print sorted(L)print '\n------- print a sorted list -----------'mylist = [Student('Alice',85),Student('Bob',90),Student('Tom',100)]print sorted(mylist)