Convert lst with two columns to dataframe?-CodePudding

 vol=list() ;df=data.frame(name=c(5,2,15,4),name=c(2,0,1,2))
 vol[[1]] <- dplyr::lst(!! names(df)[1] := df)
 df2=data.frame(dat=c(5,2,15,4),dat=c(2,0,1,2))
 vol[[2]] <- dplyr::lst(!! names(df2)[1] := df2)

How to convert this list (vol) to adata frame like this:

   A     Par    var   
 name    5      2
 name    2      0
 name   15      1
 name    4      2
 dat    5     2
 dat   2     0
 dat  15     1
 dat   4     2

CodePudding user response：

We may need to modify the column names in the list to commmon names ('Par', 'var') before binding them with map_dfr. As it is a nested list, (flatten first if it is a nested list) and then do the changes. If we need the inner list name as column, use the .id to create the column with the list names

library(dplyr)
library(purrr)
vol2 %>%   
   map_dfr(~ .x %>% rename_all(~ c("Par", "var")), .id = "A")

-output

       A Par  var
1  name  11   17
2  name  23   12
3  name  94  123
4  name  32   11
5  name   7  117
6  B.Ch  11   10
7  B.Ch  96   10
8  B.Ch   8   10
9  B.Ch  68  133
10 B.Ch   5 1167

Or using the same method in base R, flatten with c, loop over the list with lapply to rename, then create a column with Map and cbind and finally rbind the list elements

lst1 <- lapply(vol2, setNames, c("Par", "var"))
dat <- do.call(rbind, Map(cbind, A = names(lst1), lst1))
row.names(dat) <- NULL

-output

> dat
      A Par  var
1  name  11   17
2  name  23   12
3  name  94  123
4  name  32   11
5  name   7  117
6  B.Ch  11   10
7  B.Ch  96   10
8  B.Ch   8   10
9  B.Ch  68  133
10 B.Ch   5 1167

data

vol2 <- list(name = structure(list(name = c(11, 23, 94, 32, 7), name.1 = c(17, 
12, 123, 11, 117)), class = "data.frame", row.names = c(NA, 5L
)), B.Ch = structure(list(B.Ch = c(11, 96, 8, 68, 5), B.Ch.1 = c(10, 
10, 10, 133, 1167)), class = "data.frame", row.names = c(NA, 
5L)))