day7-类的特殊成员方法

#coding:utf-8

from cc13 import Dog 

print('-'*30)
d = Dog('lulu')
# 打印当前操作的对象在哪个模块
print(d.__module__)
# 打印当前操作的对象在哪个类
print(d.__class__)

class Dog(object):
    # 类的描述信息
    """此类是形容Dog这个类"""

    food = 'baozi'
 
    # 构造方法，通过类创建对象时自动触发执行
    def __init__(self,name):
        self.name = name

    def eat(self):
        print("{0} is eating".format(self.name))

    # 析构方法，当兑现在内存中释放时自动触发执行，一般无需定义
    def __del__(self):
        print("del...run")

    # 若想实例化后按obj()调用，则需定义call方法
    def __call__(self, *args, **kwargs):  
        print("running call",args,kwargs)

    # 定义对象返回值
    def __str__(self):
        return "<obj:{0}>".format(self.name)        

    # 定义索引操作(没有定义只能用obj.属性获取)，获取数据
    def __getitem__(self, key):
        print('__getitem__:',key)

    # 设置数据
    def __setitem__(self, key, value):
        print('__setitem__:',key,value)
 
    # 删除数据
    def __delitem__(self, key):
        print('__delitem__',key)
        

print('-'*30)
# 打印类的描述信息 
print(Dog.__doc__)   

print('-'*30)
d2 = Dog('lulu')
d2(1,2,3,{'name':'lulu'})

print('-'*30)
# 打印类中的所有成员，不包括实例属性
print(Dog.__dict__)
# 打印实例中所有属性，不包括类属性
print(d2.__dict__)

print('-'*30)
# 没有定义str方法前输出：<__main__.Dog object at 0x029B0F50>
print(d2)

print('-'*30)
# 自动触发__setitem__
d2['age'] = 3
# 自动触发__getitem__
print(d2['age'])
# 自动触发__delitem__
del d2['age']


>>> 
------------------------------
cc13
<class 'cc13.Dog'>
------------------------------
此类是形容Dog这个类
------------------------------
('running call', (1, 2, 3, {'name': 'lulu'}), {})
------------------------------
{'__delitem__': <function __delitem__ at 0x029AECF0>, '__module__': '__main__', '__getitem__': <function __getitem__ at 0x029AEC70>, 'food': 'baozi', '__str__': <function __str__ at 0x029AEC30>, '__doc__': '\xe6\xad\xa4\xe7\xb1\xbb\xe6\x98\xaf\xe5\xbd\xa2\xe5\xae\xb9Dog\xe8\xbf\x99\xe4\xb8\xaa\xe7\xb1\xbb', '__dict__': <attribute '__dict__' of 'Dog' objects>, '__del__': <function __del__ at 0x029AEBB0>, '__setitem__': <function __setitem__ at 0x029AECB0>, '__call__': <function __call__ at 0x029AEBF0>, '__weakref__': <attribute '__weakref__' of 'Dog' objects>, 'eat': <function eat at 0x029AEB70>, '__init__': <function __init__ at 0x029AE9B0>}
{'name': 'lulu'}
------------------------------
<obj:lulu>
------------------------------
('__setitem__:', 'age', 3)
('__getitem__:', 'age')
None
('__delitem__', 'age')