How to convert a list of nested lists of dataframes into a dataframe?

Question

I have a list with nested lists of dataframes. The structure of my data is the following one:

How can I merge all the dataframes of the nested lists into an one dataframe? In this example I want a to merge (rbind) the 4 dataframes into one! For this example think that the initial list has length 3 instead of 58.

Thank you in advance!

Answer 1

First, loop inside 0, 18 and bind_rows then use map_dfr to bind rows of the higher element ie to bind 0 and 18 together.

library(purrr)
lst=list(`0`=list(`1`=iris[1:5,]),`18`=c(`1`=list(iris[1:5,]),`2`=list(iris[1:5,])))
map_dfr(ls,~bind_rows(.,.id='id'))
#OR
bind_rows(unlist(lst,recursive = FALSE),.id = 'id')

Another more save option is to use unlist and purrr::imap to produce column id represents the full path of each dataframe

imap_dfr(unlist(lst,recursive = FALSE), ~data.frame(id=.y, .x, stringsAsFactors = FALSE))

     id Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1   0.1          5.1         3.5          1.4         0.2  setosa
2   0.1          4.9         3.0          1.4         0.2  setosa
3   0.1          4.7         3.2          1.3         0.2  setosa
4   0.1          4.6         3.1          1.5         0.2  setosa
5   0.1          5.0         3.6          1.4         0.2  setosa
6  18.1          5.1         3.5          1.4         0.2  setosa
7  18.1          4.9         3.0          1.4         0.2  setosa
8  18.1          4.7         3.2          1.3         0.2  setosa
9  18.1          4.6         3.1          1.5         0.2  setosa
10 18.1          5.0         3.6          1.4         0.2  setosa
11 18.2          5.1         3.5          1.4         0.2  setosa
12 18.2          4.9         3.0          1.4         0.2  setosa
13 18.2          4.7         3.2          1.3         0.2  setosa
14 18.2          4.6         3.1          1.5         0.2  setosa
15 18.2          5.0         3.6          1.4         0.2  setosa