R数据表：如何将数据帧列表组合成单个数据表

Question

I have the following list of data frames. I want to combine them together and store the result in a data table

A <- data.frame(A=1:3)
B <- data.frame(B=4:6)
AB_List <- list(A,B)

One of the ways to achieve this is

AB_df <- data.table(do.call("cbind", AB_List))

Is there any other way to directly get the result, without wrapping it explicitly

Answer 1

If you have data frames in a list, as.data.table will work. See example.

require(data.table)

AB_list <- lapply(seq(LETTERS), function(i) {
  df <- data.frame(A = (3*i-2):(3*i))
  names(df) <- LETTERS[i]
  df
})

as.data.table(AB_list)

To get a list of data frames you need to get a vector of data frame names using ls() and argument pattern or grep() . After that you can create a list of data frames.

df_names <- LETTERS
df_list <- mget(df_names)