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标题: 请教版主，如何显示某个attribute从属于哪个object？ [打印本页]

作者: musiker 时间: 2014-7-17 17:58
标题: 请教版主，如何显示某个attribute从属于哪个object？
本帖最后由 musiker 于 2014-7-17 17:59 编辑

class Character(object):
def __init__(self):
      self.age = 100

def printAge(self):
      print self.age

class Human(Character):
def __init__(self, name, petname):
      super(Human,self).__init__()
      self.name = name
      self.pet = Pet(petname)
def __str__(self):
      return 'my name is '+self.name

class Pet:
def __init__(self,name):
      self.name = name

def __str__(self):
      return 'i am a pet, and my name is '+self.name

jack = Human('jack','jenny')
jack.printAge()
print jack
print jack.pet
print dir(jack.pet)

在这个例子里面，jenny是Pet的instance，同时也是jack的attribute，所以只存在于jack里面，请问有没有办法或者函数显示jenny和jack的从属关系？

作者: Jorin 时间: 2014-7-17 20:33
给pet也加一个主人的属性，指向jack就好了，没有内建函数能够直接读到谁的属性包含这个对象。因为只是在jack对象内部，有一个属性指向了内存中pet的位置。

作者: musiker 时间: 2014-7-17 21:08
谢谢版主，这个办法我刚刚也想到了，能够解决问题。

class Character(object):
      def __init__(self):
            self.age = 100

      def printAge(self):
            print self.age

class Human(Character):
      def __init__(self, human_name, pet_name):
            super(Human,self).__init__()
            self.name = human_name
            self.pet = Pet(pet_name, human_name)
      def __str__(self):
            return 'my name is '+self.name

class Pet(object):
      def __init__(self,pet_name,human_name):
            self.age = 1
            self.name = pet_name
            self.owner = human_name

      def __str__(self):
            return 'i am a pet, i belongs to ' + self.owner + ', and my name is ' + self.name

jack = Human('jack','jenny')

jack.printAge()
print jack
print dir(jack)
print '\n'
print jack.pet
print jack.pet.name
print jack.pet.age
print '\n'
print type(jack.pet)
print jenny

而且我发现其实这个Pet的instance在__main__里面，其实不叫‘jenny’，而是jack.pet，所以说我的这个问题其实伪命题，吼吼！

作者: musiker 时间: 2014-7-17 21:39
尝试了一下更负责一点的例子，完全okay，

class Character(object):
def __init__(self):
self.age = 10

def printAge(self):
print self.age

class Human(Character):
def __init__(self, human_name, pet_name, pet_type='dog'):
super(Human,self).__init__()
self.name = human_name

if pet_type == 'dog':
self.pet = Dog(pet_name, human_name)
elif pet_type == 'cat':
self.pet = Cat(pet_name, human_name)
else:
self.pet = Pet(pet_name, human_name)

def __str__(self):
return 'my name is '+self.name

class Pet(object):
def __init__(self,pet_name,human_name):
self.age = 1
self.name = pet_name
self.owner = human_name

def __str__(self):
return 'i am a pet, i belongs to ' + self.owner + ', and my name is ' + self.name

class Dog(Pet):
def __init__(self,pet_name,human_name):
super(Dog,self).__init__(pet_name,human_name)

def __str__(self):
return 'i am a dog, i belongs to ' + self.owner + ', and my name is ' + self.name

class Cat(Pet):
def __init__(self,pet_name,human_name):
super(Cat,self).__init__(pet_name,human_name)

def __str__(self):
return 'i am a cat, i belongs to ' + self.owner + ', and my name is ' + self.name

jack = Human('jack','jenny','dog')
mary = Human('mary','nick','cat')
chris = Human('chris','lua','girlfriend')

print jack
print mary
print chris
print '\n'
print jack.pet
print mary.pet
print chris.pet

感叹一下，python的OOP功能真是厉害！

作者: Jorin 时间: 2014-7-17 21:47

musiker 发表于 2014-7-17 21:39
尝试了一下更负责一点的例子，完全okay，

class Character(object):

研究的很细致。加分！

作者: musiker 时间: 2014-7-17 21:57

Jorin 发表于 2014-7-17 21:47
研究的很细致。加分！

多谢版主支持！！！

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