叼花硬汉 2009-11-17 10:07 采纳率: 0%
浏览 221
已采纳

在 Python 中使用列表内涵语言创建一个词典

I like the Python list comprehension syntax.

Can it be used to create dictionaries too? For example, by iterating over pairs of keys and values:

mydict = {(k,v) for (k,v) in blah blah blah}  # doesn't work

转载于:https://stackoverflow.com/questions/1747817/create-a-dictionary-with-list-comprehension-in-python

  • 写回答

10条回答 默认 最新

  • ℡Wang Yan 2009-11-17 10:09
    关注

    In Python 2.6 and earlier, the dict constructor can receive an iterable of key/value pairs:

    d = dict((key, value) for (key, value) in iterable)
    

    From Python 2.7 and 3 onwards, you can just use the dict comprehension syntax directly:

    d = {key: value for (key, value) in iterable}
    

    Of course, you can use the iterable in any way you want (tuples and lists literals, generator comprehensions, list comprehensions, generator functions, functional composition... feel creative) as long as each element is an iterable itself of two elements:

    d = {value: foo(value) for value in sequence if bar(value)}
    
    def key_value_gen(k):
       yield chr(k+65)
       yield chr((k+13)%26+65)
    d = dict(map(key_value_gen, range(26)))
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(9条)

报告相同问题?

悬赏问题

  • ¥15 求chat4.0解答一道线性规划题,用lingo编程运行,第一问要求写出数学模型和lingo语言编程模型,第二问第三问解答就行,我的ddl要到了谁来求了
  • ¥15 Ubuntu在安装序列比对软件STAR时出现报错如何解决
  • ¥50 树莓派安卓APK系统签名
  • ¥15 maple软件,用solve求反函数出现rootof,怎么办?
  • ¥65 汇编语言除法溢出问题
  • ¥15 Visual Studio问题
  • ¥20 求一个html代码,有偿
  • ¥100 关于使用MATLAB中copularnd函数的问题
  • ¥20 在虚拟机的pycharm上
  • ¥15 jupyterthemes 设置完毕后没有效果