Question

我的数据如下

      df=data.frame(
     Id=c("001","002","003","004"),
     author=c('John Cage','Thomas Carlyle'),
     circa=c('1988', '1817'),
     quote=c('I cant understand why people are frightened of new ideas. Im frightened of the old ones.',
      'My books are friends that never fail me.')
  )
df

我想合并3列以获得下面的数据框

     df2 = data.frame(
          Id=c("001","002"),
          text = c(    
              'Author: 
              John Cage

             Circa:
             1988

             quote: 
             I cant understand why people are frightened of new ideas. Im frightened of the old ones.
             ',
               'Author: 
               Thomas Carlyle

             Circa:
             1817

             quote: 
             My books are friends that never fail me.
              '
         )
         )
     df2

我知道我可以使用 tidyr 中的 paste 或 unite ，但是如何将列名传递到新创建的列中专栏？

Answer 1

这里是base R的解决方案，其中使用了paste0()。也许以下代码可以帮助您实现

res <- cbind(df[1],text = apply(apply(df[-1], 1, function(v) paste0(names(df[-1]),": ",v)), 2, paste0, collapse = "\n"))

如此

> res
   Id                                                                                                                            text
1 001 author: John Cage\ncirca: 1988\nquote: I cant understand why people are frightened of new ideas. Im frightened of the old ones.
2 002                                            author: Thomas Carlyle\ncirca: 1817\nquote: My books are friends that never fail me.

数据

df <- structure(list(Id = structure(1:2, .Label = c("001", "002"), class = "factor"), 
    author = structure(1:2, .Label = c("John Cage", "Thomas Carlyle"
    ), class = "factor"), circa = structure(2:1, .Label = c("1817", 
    "1988"), class = "factor"), quote = structure(1:2, .Label = c("I cant understand why people are frightened of new ideas. Im frightened of the old ones.", 
    "My books are friends that never fail me."), class = "factor")), class = "data.frame", row.names = c(NA, 
-2L))

Answer 2

您可以获取长格式的数据，然后按组paste。

library(dplyr)

df %>%
  tidyr::pivot_longer(cols = -Id) %>%
  group_by(Id) %>%
  summarise(text = paste(name, value, sep = ":", collapse = "\n"))

# A tibble: 4 x 2
#  Id    text                                                                    
#  <fct> <chr>                                                                   
#1 001   "author:John Cage\ncirca:1988\nquote:I cant understand why people are f…
#2 002   "author:Thomas Carlyle\ncirca:1817\nquote:My books are friends that nev…
#3 003   "author:John Cage\ncirca:1988\nquote:I cant understand why people are f…
#4 004   "author:Thomas Carlyle\ncirca:1817\nquote:My books are friends that nev…

Answer 3

我们可以在melt中使用data.table

library(data.table)
melt(setDT(df), id.var = 'Id')[, .(text = paste(variable, 
       value, sep=":", collapse="\n")), Id]
#     Id                                                                                                                         text
#1: 001 author:John Cage\ncirca:1988\nquote:I cant understand why people are frightened of new ideas. Im frightened of the old ones.
#2: 002                                            author:Thomas Carlyle\ncirca:1817\nquote:My books are friends that never fail me.

合并多列，将变量名称保留为数据的一部分

3 个答案: