r - 将三个数据框的内容合并到 R 中的一列(跨多列)

Question

我面临的挑战比我在这里意识到的要大:Merge contents from three dataframes into one column ，因此我的新问题。我有以下三个数据框。

 df1 <- data.frame(c("A", "B", "C", "D"), 
      c("text1", "texta", "textk", "textx"),
      c("texti", "textI", "texti", "textI"))
 names(df1) <- c('dummy_1', 'dummy_2', 'dummy_3')
 df2 <- data.frame(c("A", "B", "C", "D"), 
      c("text2", "textb", "textl", "texty"), 
      c("textii", "textII", "textii", "textII"))
 names(df2) <- c('dummy_1', 'dummy_2', 'dummy_3')
 df3 <- data.frame(c("A", "B", "C", "D"), 
      c("text3", "textc", "textm", "textz"),
      c("textiii", "textIII", "textiii", "textIII"))
 names(df3) <- c('dummy_1', 'dummy_2', 'dummy_3')

如何将 dfs df1、df2 和 df3 中每一列 dummy_2 和每一列 dummy_3 的文本合并为一列，分开通过“\n”？所以期望的结果是这个 data.frame:

 dummy_1    dummy2_merge                 dummy3_merge
 A          text1 \n text2 \n text3      texti \n textii \n textiii
 B          texta \n textb \n textc      textI \n textII \n textIII
 C          textk \n textl \n textm      texti \n textii \n textiii
 D          textx \n texty \n textz      textI \n textII \n textIII

感谢您的任何建议。

Answer 1

使用data.table合并替换

library(data.table)

setDT(df1);setDT(df2);setDT(df3)

df1[df2, on = .(dummy_1), `:=` (dummy_2 = paste0(dummy_2, ' \n ', i.dummy_2),
                                dummy_3 = paste0(dummy_3, ' \n ', i.dummy_3))][]
df1[df3, on = .(dummy_1), `:=` (dummy_2 = paste0(dummy_2, ' \n ', i.dummy_2),
                                dummy_3 = paste0(dummy_3, ' \n ', i.dummy_3))][] 

导致

   dummy_1                 dummy_2                    dummy_3
1:       A text1 \n text2 \n text3 texti \n textii \n textiii
2:       B texta \n textb \n textc textI \n textII \n textIII
3:       C textk \n textl \n textm texti \n textii \n textiii
4:       D textx \n texty \n textz textI \n textII \n textIII