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Python类和_uinit___;构造函数,如何生成列表变量?_Python_List_Class_Constructor_Getter Setter - Fatal编程技术网

Python类和_uinit___;构造函数,如何生成列表变量?

Python类和_uinit___;构造函数,如何生成列表变量?,python,list,class,constructor,getter-setter,Python,List,Class,Constructor,Getter Setter,嗨,我正在创建一个有购物清单的类。代码似乎有效,但我不确定是否正确。我是否打算将shopping=[]放在构造函数中,这是做什么的? 非常感谢 class Shopping: def __init__(self, shopping = []): self.__shopping = [] def set_shopping(self, shopping): self.__shopping = shopping def get

嗨,我正在创建一个有购物清单的类。代码似乎有效,但我不确定是否正确。我是否打算将shopping=[]放在构造函数中,这是做什么的? 非常感谢

class Shopping:
    def __init__(self, shopping = []): 
        self.__shopping = []

   
    def set_shopping(self, shopping): 
          self.__shopping  = shopping
    def get_shopping(self): 
        return self.__shopping

shoppinglist = Shopping()
shoppinglist = ['apples', 'pears', 'bread']
以下是一个例子:

class Shopping:
    def __init__(self, shopping = []): 
        self.__shopping = []
    
    def set_shopping(self, shopping): 
          self.__shopping  = shopping
    
    def get_shopping(self): 
        return self.__shopping
    
    def add_article(self, article): 
          self.__shopping.append(article)

    def get_article(self, index): 
          return self.__shopping[index]

    shoppinglist = Shopping()
    shoppinglist.set_shopping(['apples', 'pears', 'bread'])
    shoppinglist.add_article('oranges')
    shoppinglist.get_article(0) #==> 'apples'
    shoppinglist.get_article(3) #==> 'oranges'

构造函数中的shopping=[]创建一个空列表,该列表对于实例是唯一的,因此,是的,您的方法似乎是正确的。如果您在构造函数之外声明了list属性,那么该类的所有实例都会使用它。非常感谢,我是否也需要将shopping[]放在setter中?因为我只有shopping变量,settershopping中没有列表,所以不应该多次声明它。目前您无法在列表中添加文章,您可以设置整个列表。所以你可以添加像self.\u shopping.append(newArticle)这样的东西,如果你愿意的话,可以用另一种方法。明白了!非常感谢。