r语言 - 从长度不兼容的列表中选择元素

Question

给定列表的如下结构:

x <- list(list(Main = list(one = list(tlv = 1, beta = 2), two = "three", three = 4,list_a = list(list(value_1 = "a1", value_2 = "b", c = "c")))),
list(Main = list(one = list(tlv = 2, beta = 6), two = "seven", three = 8,list_a = list(list(value_1 = "aa2", value_2 = "bb", c = "cc")))),
list(Main = list(one = list(tlv = 3),list_a = list(list(value_1 = c("aaa3", "aaaa4"), value_2 = c("bbb", "bbbb"), c = c("ccc", "ccc"))))))

我正在尝试创建一个数据框架的结构如下:

tlv | value_1  
1 | a1       
2 | aa2      
3 | aaa3     
3 | aaaa4

到目前为止，我不得不这样做:

library(tidyverse)
tibble::tibble(
tlv = map(x, list(1,1,"tlv"), .default = NA) %>% unlist(),
value = map(x, list(1,"list_a", 1, "value"), .default = NA) %>% unlist())

导致以下错误:

Error: Tibble columns must have compatible sizes.
* Size 3: Existing data.
* Size 4: Column `value`.
i Only values of size one are recycled.

给定列表的结构(其中一个变量为3个值，另一个变量为4个值)，这是有意义的。但是我没有看到将值链接到列表的父元素的解决方案。这样每个'value'也会得到相应的'tlv'值。如何解决这个问题有什么指导吗?

Answer 1

找到了一个解决方案，这是一个技巧:

x %>%
map_df(~tibble(
tlv = .$Main$one$tlv,
value = .$Main$list_a[[1]]$value_1))

Answer 2

另一种选择:

library(tidyverse)
value_1 <-
map_depth(x, 4, pluck, "value_1", .ragged = TRUE) %>%
map(unlist, use.names = FALSE)
tlv  <-
map_depth(x, 3, pluck, "tlv") %>%
map_dbl(unlist, use.names = FALSE)
df <-
tibble(tlv = tlv, value_1 = value_1) %>%
unnest_auto(col = value_1)