从列表理解创建有序的dict？ [英] create ordered dict from list comprehension?

问题描述

以下是列表解析：

其中

• L 是有序字典列表（即collection.OrderedDict的对象），其中字典具有相同的键集。




• d 是另一个有序字典，它也具有与先前订购的字典相同的一组键。




• 对于每个键， d [key] 是可以应用于 L [i] [key] 的功能，即 d [key]（L [i] [key]） 。

所有给定的字典都是排序的，并且键的顺序相同。

但代码将创建无序字典。与给定的订阅字典相同的关键顺序如何创建一个有序的字典？

解决方案

collections.OrderedDict 只不过是一个dict，其中包含元素的顺序。所以你可以用它的构造函数创建一个这样的

  [OrderedDict（（k，d [k]（v））for k，v）in l.iteritems（））for L in L] 
  

Here is a list comprehension:

L = [{k: d[k](v) for (k, v) in l.iteritems()} for l in L]

where

• L is a list of ordered dictionaries (i.e. objects of collections.OrderedDict), where the dictionaries have the same set of keys.

• d is another ordered dictionary, which also has the same set of keys as the previous ordered dictionaries.

• For each key, d[key] is a function which can apply to L[i][key], i.e. d[key](L[i][key]).

All the given dictionaries are ordered dicts, and have the same order in their keys.

But the code will create an unordered dictionary. How can I create an ordered dict in the same key order as the given ordered dictionaries?

解决方案

collections.OrderedDict is nothing but a dict, which remembers the order in which the elements are included in it. So you can create one with its constructor like this

[OrderedDict((k, d[k](v)) for (k, v) in l.iteritems()) for l in L]

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