打印Python字典中的所有唯一值 [英] Print all Unique Values in a Python Dictionary

问题描述

我在Python中遇到了一个小问题（我的程序现在在3.2.3版本）。

我有一个看起来像这样的字典这只是一个例子，实际上是从另一篇文章中获取的）：

  [{abc：movies}，{ abc：sports}，{abc：music}，{xyz：music}，{pqr：music}，{pqr pqr：sports}，{pqr：news}，{pqr：sports}] 
  

我想简单地打印（）一个唯一值的列表，消除重复。在这个列表的最后，我想打印字典中唯一值的数量：

 电影
运动
音乐
新闻
 
 4 
  

任何帮助是赞赏。还有一些其他的帖子，我发现这是有些相关的，但我不知道Python足够好地应用到这个具体问题。

解决方案

使用设置，因为它们只包含唯一的项目。

 >>> lis = [{abc：movies}，{abc：sports}，{abc：music}，{xyz：music}，{pqr }，{pqr：movies}，{pqr：sports}，{pqr：news}，{pqr：sports}] 
>> ;> s = set（对于dic.values（）中的val的dic的val）val 
>>>> s 
 set（['movies'，'news'，'music'，'sports']）
  

循环此集合以获取预期的输出：

  for x in s：
 print x 
打印len（s）#print循环后设置的长度
 ... 
电影
新闻
音乐
运动
 4 
  

此行 s = set（val for dic in lis for val in dic.values（））大致相当于：

  s = set（）
 for dic in lis：
 for val in dic.values（）：
 s.add（val）
  

I'm struggling with a minor problem in Python (my program is in version 3.2.3 right now).

I have a dictionary that looks like this (this is just an example, actually taken from another post here):

[{"abc":"movies"}, {"abc": "sports"}, {"abc": "music"}, {"xyz": "music"}, {"pqr":"music"}, {"pqr":"movies"},{"pqr":"sports"}, {"pqr":"news"}, {"pqr":"sports"}]

I want to simply print() a list of unique values, eliminating duplicates. At the end of this list, I would like to print the number of unique values in the dictionary:

movies
sports
music
news

4

Any help is appreciated. There are some other posts here I found that were somewhat related, but I don't know Python well enough to apply it to this specific problem.

解决方案

Use set here as they only contain unique items.

>>> lis = [{"abc":"movies"}, {"abc": "sports"}, {"abc": "music"}, {"xyz": "music"}, {"pqr":"music"}, {"pqr":"movies"},{"pqr":"sports"}, {"pqr":"news"}, {"pqr":"sports"}]
>>> s = set( val for dic in lis for val in dic.values())
>>> s 
set(['movies', 'news', 'music', 'sports'])

Loop over this set to get the expected output:

for x in s:                                
    print x
print len(s)   #print the length of set after the for-loop
... 
movies
news
music
sports
4

This line s = set( val for dic in lis for val in dic.values()) is roughly equivalent to:

s = set()
for dic in lis:
   for val in dic.values():
      s.add(val)

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