Python中类的使用

#coding=utf8
'''
Created on 2011-6-12
@author: hufei
'''
name = 'hufei'
if not name:
    pass
else:
    class Person:                                       # class can be defined in a branch of 'if' statement
        def __init__(self,name,age):
            self.name = name
            self.age = age
        def __str__(self):
            return u"%s:%d" % (self.name, self.age)
        def say_hello(self):
            print 'Hello'
    
    def say_hi(name):
        print u"%s:hi" % name
    
    def say_hello(name):
        print u"%s: hello!" % name
    
    maimai = Person('maimai',22)
    
    #attributes need not be declared, they spring into existence when they are first assigned
    maimai.sex = 'Female'           
    print maimai                    #invoke __str__
    
    print maimai.sex
    print type(maimai.age)
    print type(maimai.say_hello)    # <type 'instancemethod'>
    maimai.say_hello = say_hi       # methodname just looks like a reference, can be modified
    maimai.say_hello('Jack')
    maimai.say_hi = say_hello       # method of Class can be added dynamically
    maimai.say_hi('Tom')
            

python中的类的语法与java相比，灵活多变。相比而言，java是严格而规范的语言，而python给人更加随意的感觉。