用于在Python中删除重复项的迭代器对象

大家好，我正试图弄清楚如何使用Python创建一个迭代器对象，它可以删除重复项或更多项，从而省略重复项

例如，我有一个列表（1，2，3，3，4，4，5），我得到（1，2，3，4，5）

我知道为了得到迭代器对象，我必须创建它。因此：

Class Unique:
    def __init__(self, n):
         self.i = 0
         self.n = n  

    def __iter__(self):
         return self

    def __next__(self):
        if self.i < self.n:

类唯一性：
定义初始化（self，n）：
self.i=0
self.n=n
定义（自我）：
回归自我
定义下一个（自我）：
如果self.i

---

实际上，我并不完全确定在这个问题上下一步该怎么办。提前感谢您的任何意见或帮助

最好创建一个生成器函数，如下所示

>>> def unique_values(iterable):
...     seen = set()
...     for item in iterable:
...         if item not in seen:
...             seen.add(item)
...             yield item
... 

>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> def unique_values(iterable):
...     it = iter(iterable)
...     previous = next(it)
...     yield previous
...     for item in it:
...         if item != previous:
...             previous = item
...             yield item
>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> class Unique:
...     def __init__(self, iterable):
...         self.__it = iter(iterable)
...         self.__seen = set()
... 
...     def __iter__(self):
...         return self
... 
...     def __next__(self):
...         while True:
...             next_item = next(self.__it)
...             if next_item not in self.__seen:
...                 self.__seen.add(next_item)
...                 return next_item
... 
>>> for item in Unique((1, 2, 3, 3, 4, 4, 5)):
...     print(item)
... 
1
2
3
4
5

然后您可以创建一个唯一值的元组，如下所示

>>> def unique_values(iterable):
...     seen = set()
...     for item in iterable:
...         if item not in seen:
...             seen.add(item)
...             yield item
... 

>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> def unique_values(iterable):
...     it = iter(iterable)
...     previous = next(it)
...     yield previous
...     for item in it:
...         if item != previous:
...             previous = item
...             yield item
>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> class Unique:
...     def __init__(self, iterable):
...         self.__it = iter(iterable)
...         self.__seen = set()
... 
...     def __iter__(self):
...         return self
... 
...     def __next__(self):
...         while True:
...             next_item = next(self.__it)
...             if next_item not in self.__seen:
...                 self.__seen.add(next_item)
...                 return next_item
... 
>>> for item in Unique((1, 2, 3, 3, 4, 4, 5)):
...     print(item)
... 
1
2
3
4
5

---

如果您确信数据总是被排序的，那么您可以避免创建集合，只跟踪以前的数据，如下所示

>>> def unique_values(iterable):
...     seen = set()
...     for item in iterable:
...         if item not in seen:
...             seen.add(item)
...             yield item
... 

>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> def unique_values(iterable):
...     it = iter(iterable)
...     previous = next(it)
...     yield previous
...     for item in it:
...         if item != previous:
...             previous = item
...             yield item
>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> class Unique:
...     def __init__(self, iterable):
...         self.__it = iter(iterable)
...         self.__seen = set()
... 
...     def __iter__(self):
...         return self
... 
...     def __next__(self):
...         while True:
...             next_item = next(self.__it)
...             if next_item not in self.__seen:
...                 self.__seen.add(next_item)
...                 return next_item
... 
>>> for item in Unique((1, 2, 3, 3, 4, 4, 5)):
...     print(item)
... 
1
2
3
4
5

---

您可以使用类编写迭代器对象，如下所示

>>> def unique_values(iterable):
...     seen = set()
...     for item in iterable:
...         if item not in seen:
...             seen.add(item)
...             yield item
... 

>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> def unique_values(iterable):
...     it = iter(iterable)
...     previous = next(it)
...     yield previous
...     for item in it:
...         if item != previous:
...             previous = item
...             yield item
>>> tuple(unique_values((1, 2, 3, 3, 4, 4, 5)))
(1, 2, 3, 4, 5)

>>> class Unique:
...     def __init__(self, iterable):
...         self.__it = iter(iterable)
...         self.__seen = set()
... 
...     def __iter__(self):
...         return self
... 
...     def __next__(self):
...         while True:
...             next_item = next(self.__it)
...             if next_item not in self.__seen:
...                 self.__seen.add(next_item)
...                 return next_item
... 
>>> for item in Unique((1, 2, 3, 3, 4, 4, 5)):
...     print(item)
... 
1
2
3
4
5

---

您可以参考

如果保留原始顺序不重要，只需使用

设置

：

values = (1, 3, 2, 5, 4, 3)
unique_values = set(values)
print unique_values
(1, 2, 3, 4, 5)

---

我了解如何创建生成器函数，但我想知道如何为同一方法创建迭代器对象。我正在复习考试，所以这真的很有帮助！请记住，这假设

iterable

中的项目是可散列的（以便可以将它们添加到集合中）。@thefourtheye谢谢，这很有意义，谢谢您的参考答案！为什么要创建一个新类，而不是使用

集

或子类化

集

？这更多的是一个练习来实现使用迭代器对象（在我的类中进行测验），它有助于理解迭代器是如何工作的。我理解使用“set”作为内置函数，但如果有人能帮我写这篇文章，我将不胜感激。