从字符串创建嵌套列表结构 [英] Create nested list structure from a string

问题描述

我有一个由n个子字符串组成的字符串.看起来可能像这样:

I have a string that is a composite of n substrings. It could look like this:

string <- c("A_AA", "A_BB", "A_BB_AAA", "B_AA", "B_BB", "B_CC")

此字符串中的每个子组件都由"_"分隔.在此，第一级由值"A"和"B"组成，第二级由"AA"，"BB"和"CC"组成，第三级由"AAA"组成.更深层的嵌套是可能的，解决方案应扩展到这些情况.嵌套不一定是平衡的，例如"A"只有两个孩子，而"B"有三个孩子，但它也有一个孙子，而"B"没有.

Every subcomponent in this string is separated from any other by "_". Here, the first level consists of the values "A" and "B", the second level of "AA", "BB" and "CC", the third level of "AAA". Deeper nestings are possible and the solution should extend to those cases. The nestings are not necessarily balanced, e.g. "A" only has two children, while "B" has three, but it also has a grandchild which "B" has not.

本质上，我想在某种R对象(最好是列表)中的此字符串中重新创建嵌套结构.因此，嵌套列表结构将如下所示:

Essentially, I want to recreate the nested structure in this string in some kind of R object, preferably a list. Thus, the nested list structure that would look like this:

list("A" = list("AA", "BB" = list("AAA")),
"B" = list("AA", "BB", "CC"))

> $A
  $A[[1]]

  [1] "AA"
  $A$BB
  $A$BB[[1]]
  [1] "CCC"

  $B
  $B[[1]]
  [1] "AA"

  $B[[2]]
  [1] "BB"

  $B[[3]]
  [1] "CC"

对此有任何帮助

推荐答案

您可以将其制作成矩阵而不必大惊小怪...

You can make it into a matrix without too much fuss...

string <- c("A_AA", "A_BB", "A_BB_AAA", "B_AA", "B_BB", "B_CC")

splitted<-strsplit(string,"_")
cols<-max(lengths(splitted))
mat<-do.call(rbind,lapply(splitted, "length<-", cols))

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