是否可以将列表转换为嵌套的键字典*无需*递归?

2022-01-24 00:00:00 python 递归 list dictionary iteration

问题描述

假设我有一个如下列表:

Supposing I had a list as follows:

mylist = ['a','b','c','d']

是否可以从这个列表中不使用使用递归/递归函数创建以下字典?

Is it possible to create, from this list, the following dict without using recursion/a recursive function?

{
  'a': {
    'b': {
      'c': {
        'd': { }
      }
    }
  }
}

解决方案

对于简单的情况，简单的迭代和构建，从头到尾都可以:

For the simple case, simply iterate and build, either from the end or the start:

result = {}
for name in reversed(mylist):
    result = {name: result}

或

result = current = {}
for name in mylist:
    current[name] = {}
    current = current[name]

第一个解决方案也可以使用 reduce():

The first solution can also be expressed as a one-liner using reduce():

reduce(lambda res, name: {name: res}, reversed(mylist), {})

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