Converting a list to a data frame

On Wed, May 2, 2018 at 11:53 AM, Jeff Newmiller
<jdnewmil at dcn.davis.ca.us> wrote:

Another approach:

########
library(tidyr)
L <- list( A = data.frame( x=1:2, y=3:4 )
          , B = data.frame( x=5:6, y=7:8 )
          )
D <- data.frame( Type = names( L )
                , stringsAsFactors = FALSE
                )
D$data <- L
unnest(D, data)
#>   Type x y
#> 1    A 1 3
#> 2    A 2 4
#> 3    B 5 7
#> 4    B 6 8
########

I think a slightly more idiomatic tidyverse solution is dplyr::bind_rows()

l <- list(
   A = data.frame(x = 1:2, y = 3:4),
   B = data.frame(x = 5:6, y = 7:8)
)

dplyr::bind_rows(l, .id = "type")
#>   type x y
#> 1    A 1 3
#> 2    A 2 4
#> 3    B 5 7
#> 4    B 6 8

This also has the advantage of returning a data frame when the inputs
are data frames.

Hadley