bind rows on list of elements to list of data.frame

Question

I have list of R elements and want to bind row all elements within the list. Each row binds to data.frame based on the column class. The actual data is quite large and each class has different columns. Here is sample

df_list <- list()
df_list[[1]] <- data.frame(Class = "x", y = 1, stringsAsFactors = F)
df_list[[2]] <- data.frame(Class = "x", y = 2, stringsAsFactors = F)
df_list[[3]] <- data.frame(Class = "a", y = 3, stringsAsFactors = F)
df_list[[4]] <- data.frame(Class = "x", y = 4, stringsAsFactors = F)
df_list[[5]] <- data.frame(Class = "a", y = 5, stringsAsFactors = F)

Desired output, looking this to be done programmatically

df_list_out <- list()

df_list_out[[1]] <- bind_rows(data.frame(Class = "x", y = 1, 
                                         stringsAsFactors = F),
                              data.frame(Class = "x", y = 2, 
                                          stringsAsFactors = F),
                              data.frame(Class = "x", y = 4, 
                                           stringsAsFactors = F))


df_list_out[[2]] <- bind_rows(data.frame(Class = "a", y = 3, 
                                           stringsAsFactors = F),
                              data.frame(Class = "a", y = 5, 
                                         stringsAsFactors = F))

Answer 1

One way would be to rbind the list of dataframes together and then split

temp <- do.call(rbind, df_list)
split(temp, temp$Class)

#$a
#  Class y
#3     a 3
#5     a 5

#$x
#  Class y
#1     x 1
#2     x 2
#4     x 4

---

In dplyr, we can do

library(dplyr)

df_list %>% bind_rows() %>% group_split(Class)