Python 3.x Python用户列表模块

我是Python新手。我正在考虑使用一个名为Ulist的类来重写add、append和extend方法，这样重复的值就不会被这些操作添加到列表中。下面是我的代码。但问题是，当我试图打印我的列表时，结果是一个空列表。你能帮我知道我的代码哪部分是错的吗？谢谢

class Ulist(UserList):
    def __init__(self, data):
        UserList.__init__(self)
        self.list = data

    def __add__(self, newdata):
        for i in newdata:
            if i in self.list:
                print (i, "not be added to the list")
            else:
                self.list += [i]
        return self.list

    def append(self,newdata):
        for i in newdata:
            if i in self.list:
                 print (i, "not be added to the list")
            else:
                self.list.append(i)
        return self.list

    def extend(self,newdata):
         for i in newdata:
            if i in self.list:
                  print (i, "not be added to the list")
            else:
                self.list.extend(i)
         return self.list

mylist = Ulist([1,2,3])

mylist.__add__([1,2])
print (mylist)

---

重构你的self.list->self.data

class Ulist(UserList):
    def __init__(self, data):
        UserList.__init__(self)
        self.data = data

    def __add__(self, newdata):
        for i in newdata:
            if i in self.data:
                print (i, "not be added to the list")
            else:
                self.data += [i]
        return self.data

    def append(self, newdata):
        for i in newdata:
            if i in self.data:
                 print (i, "not be added to the list")
            else:
                self.data.append(i)
        return self.data

    def extend(self, newdata):
         for i in newdata:
            if i in self.data:
                  print (i, "not be added to the list")
            else:
                self.data.extend(i)
         return self.data

mylist = Ulist([1,2,3])

mylist.__add__([1,2])
print (mylist)

---

UserList

不将其数据存储为

self.list

它将自身存储为

self.data

：

from collections import UserList
class Ulist(UserList):
    def __init__(self, data):
        UserList.__init__(self)
        self.data = data

    def __add__(self, newdata):
        for i in newdata:
            if i in self.data:
                print(i, "not be added to the list")
            else:
                self.data += [i]
        return self.data

    def append(self, newdata):
        for i in newdata:
            if i in self.data:
                 print(i, "not be added to the list")
            else:
                self.data.append(i)
        return self.data

    def extend(self, newdata):
         for i in newdata:
            if i in self.data:
                  print(i, "not be added to the list")
            else:
                self.data.extend(i)
         return self.data


mylist = Ulist([1, 2, 3])

mylist.__add__([1, 2])
print(mylist)

输出：

1 not be added to the list
2 not be added to the list
[1, 2, 3]

---

非常感谢你！