r - 如何修改多级嵌套 R 列表中的元素？

Question

我需要做的是替换 type 的所有值嵌套列表第 4 层上的向量 a通过transcodification上的相应人员tibble 并为列表的其余部分保持相同的结构:

a = list(
    a1 = list(
      b1 = list(
        c1 = list(
          type = c(1,3),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        ),
        c2 = list(
          type = c(2,3,6),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        )
      ),
      b2 = list("foo")
    ),
    a2 = list(
      b1 = list(
        c3 = list(
          type = c(5),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        ),
        c4 = list(
          type = c(2,3,6),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        )
      ),
      b2 = list("foo")
    ),
    a3 = list(
      b1 = list(
        c5 = list(
          type = c(6),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        ),
        c6 = list(
          type = c(1,2,3,5),
          attribute1 = runif(3,0,1),
          attribute2 = list(d = rpois(1,1))
        )
      ),
      b2 = list("foo")
    )
  )
  
transcodification = tibble(origin = c(1,2,3,4,5,6),
                           replacement = c("Peter","Jake","Matthew","Suzan","Christina","Margot"))

是否可以使用 purrr功能 ?

Answer 1

你可以从purrr的modify函数开始

modify_depth(a, 3, ~map(., ~str_replace_all(., transcodification %>% pull(2) %>% set_names(1:length(.)))))
$a1
$a1$b1
$a1$b1$c1
$a1$b1$c1$type
[1] "Peter"   "Matthew"

$a1$b1$c1$attribute1
character(0)

$a1$b1$c1$attribute2
character(0)


$a1$b1$c2
$a1$b1$c2$type
[1] "Jake"    "Matthew" "Margot" 

$a1$b1$c2$attribute1
character(0)

$a1$b1$c2$attribute2
character(0)



$a1$b2
$a1$b2[[1]]
$a1$b2[[1]][[1]]
[1] "foo"

但这将分别在 b2 中引入额外的列表层。

如果 "type" 总是在第一棵树上，那么您可以尝试不做任何进一步的转换

modify_depth(a, 3, ~modify_at(.,1, ~str_replace_all(., transcodification %>% pull(2) %>% set_names(1:length(.)))))

或在每个数字向量上

modify_depth(a, 3, ~modify_if(., is.numeric, ~str_replace_all(., transcodification %>% pull(2) %>% set_names(1:length(.)))))

对于替换，我们将使用 stringr 的 str_replace_all，而替换是使用这样的命名向量完成的:

transcodification %>% pull(2) %>% set_names(1:length(.))
      1           2           3           4           5           6 
"Peter"      "Jake"   "Matthew"     "Suzan" "Christina"    "Margot"