将列名附加到值的开头，并用下划线分隔

Question

如何将列名附加到列中每个值的开头，用“_”分隔，跳过第一列（或者，等效地，选择第二和第三列）？

multiple=data.frame(id=c(1:6), 
     status=c("good", "bad", "ok", "ok", "good", "bad"), 
     breakfast=c("eggs", "sausage", "eggs", "sausage", "sausage", "eggs"))
# Desired:
#id status breakfast
#1  status_good breakfast_eggs
#2  status_bad  breakfast_sausage
#3  status_ok   breakfast_eggs
#4  status_ok   breakfast_sausage
#5  status_good breakfast_sausage
#6  status_bad  breakfast_eggs

Answer 1

这是一个带有 tidyverse 的选项，我们循环 across 列并粘贴相应的列名 (cur_column())

library(dplyr)
library(stringr)
multiple %>%
    mutate(across(c(status, breakfast), ~ str_c(cur_column(), "_", .)))

-输出

#  id      status         breakfast
#1  1 status_good    breakfast_eggs
#2  2  status_bad breakfast_sausage
#3  3   status_ok    breakfast_eggs
#4  4   status_ok breakfast_sausage
#5  5 status_good breakfast_sausage
#6  6  status_bad    breakfast_eggs

Answer 2

在 base R 中，我们可以使用 Map :

multiple[-1] <- Map(function(x, y) paste(x, y, sep = '_'), 
                     names(multiple)[-1], multiple[-1])

或 purrr 的 imap_dfc :

multiple[-1] <- purrr::imap_dfc(multiple[-1], ~paste(.y, .x, sep = '_'))
multiple

#  id      status         breakfast
#1  1 status_good    breakfast_eggs
#2  2  status_bad breakfast_sausage
#3  3   status_ok    breakfast_eggs
#4  4   status_ok breakfast_sausage
#5  5 status_good breakfast_sausage
#6  6  status_bad    breakfast_eggs

将列名附加到值的开头，并用下划线分隔

Append column name to the beginning of values separated by an underscore

r

dataframe

stringr

dplyr