自动合并列，其中合并的值在容器中用定界符分隔

Question

我有一个大数据框，其中很多列的列名称中都有 .。这是我在下面示例中的方法：

#this somewhat resembles what we have in hand
df <- data.frame(id= c("HD1", "HD2", "HD3", "HD4"),
                 mon.1= c(1, 0, 1, 4),
                 mon.2= c("a", "b", "c", "d"),
                 mon.2.4.1...1= c("#ji", "#ki", NA, "#ui"),
                 tue.6= c("1", "2", "3", "4"),
                 tue= c(190, 2345, 41, 89),
                 heh= c("1mn", "2a", "g78", "asd324"),
                 wed= c(1890, 9002, 14341, 657),
                 wed.01= c(NA, "@ksdf", NA, NA),
                 thu.0234= c("@jksdff", "@sfd", "@kukg.676", "@jdkfjk"),
                 rating= c(1,2,3,4))

#in order to collapse the columns, we can apply a mapply variant

#here i attach a new column to original df named combined1 which collapses all mon.....
df<- within(df, 
       combined1 <- Map(list, as.character(mon.1),
                        as.character(mon.2),
                        as.character(mon.2.4.1...1)))

#process repeats for others
df <- within(df,
         combined2 <- Map(list, as.character(tue.6),
                        as.character(tue)))

df <- within(df,
        combined3 <- Map(list, as.character(wed),
                        as.character(wed.01)))

产生逗号分隔的列 Combined1、Combined2、Combined3 :

# A tibble: 4 x 14
  id    mon.1 mon.2 mon.2.4.1...1 tue.6   tue heh     wed wed.01 thu.0234 rating
  <fct> <dbl> <fct> <fct>         <fct> <dbl> <fct> <dbl> <fct>  <fct>     <dbl>
1 HD1       1 a     #ji           1       190 1mn    1890 NA     @jksdff       1
2 HD2       0 b     #ki           2      2345 2a     9002 @ksdf  @sfd          2
3 HD3       1 c     NA            3        41 g78   14341 NA     @kukg.6~      3
4 HD4       4 d     #ui           4        89 asd3~   657 NA     @jdkfjk       4
# ... with 3 more variables: combined1 <named list>, combined2 <named list>,
#   combined3 <named list>

我的问题是 mon、tue 和 wed 大约有 20-30 列，我在创建一个方法时遇到问题，该方法将读取所有内容，例如， wed、wed1.43654、wed.46 等。这样我就不必手动输入它们了。非常感谢您的帮助！

编辑像这样

> df[,11:14]
  rating combined1 combined2   combined3
1      1 1, a, #ji    1, 190    1890, NA
2      2 0, b, #ki   2, 2345 9002, @ksdf
3      3  1, c, NA     3, 41   14341, NA
4      4 4, d, #ui     4, 89     657, NA

Answer 1

这是一个选项，我们删除以 . ('nm1') 开头的列名称的后缀部分，创建一个频率 table，提取具有多个的名称count ('nm2')，遍历这些唯一名称，使用 grep 从数据集中提取列，并将其分配给创建 'combined' 列

nm1 <- sub("\..*", "", names(df))
nm2 <- names(which(table(nm1) > 1))
df[paste0('combined', seq_along(nm2))] <- lapply(nm2, 
        function(x) df[grep(x, names(df))])



df$combined1
#  mon.1 mon.2 mon.2.4.1...1
#1     1     a           #ji
#2     0     b           #ki
#3     1     c          <NA>
#4     4     d           #ui

如果我们希望这是一个 list 列

df[paste0('combined', seq_along(nm2))] <- lapply(nm2, 
        function(x) 
        apply(df[grep(x, names(df))], 1, function(x) as.list(c(x))))


df
#   id mon.1 mon.2 mon.2.4.1...1 tue.6  tue    heh   wed wed.01  thu.0234 rating combined1 combined2    combined3
#1 HD1     1     a           #ji     1  190    1mn  1890   <NA>   @jksdff      1 1, a, #ji   1,  190     1890, NA
#2 HD2     0     b           #ki     2 2345     2a  9002  @ksdf      @sfd      2 0, b, #ki   2, 2345  9002, @ksdf
#3 HD3     1     c          <NA>     3   41    g78 14341   <NA> @kukg.676      3  1, c, NA   3,   41    14341, NA
#4 HD4     4     d           #ui     4   89 asd324   657   <NA>   @jdkfjk      4 4, d, #ui   4,   89      657, NA

Answer 2

WolfgangBagdanow-

Yeah please, It would be nice if can have them in a list form or something because I will writing them to a file. My goal is to cut-down unnecessary column creations. I put down how I would like in my question above

这是对@akrun 的第二个答案的扩展。如果您决定将此 df 写入 csv 文件，那么请知道 readr、data.table 和 base 写入 csv 方法都不起作用，因为它们没有实现方法然而，将列表写入 csv 文件（据我所知）。为了将具有列表列的数据框写入 csv 文件，您需要这样的东西-

#@akrun 's list method-
#df <- data.frame(...)

df[paste0('combined', seq_along(nm2))] <- lapply(nm2, 
        function(x) 
        apply(df[grep(x, names(df))], 1, function(x) as.list(c(x))))

#------------------------------------
set_lists_to_chars <- function(x) {
  if(class(x) == 'list') {
    y <- paste(unlist(x[1]), sep='', collapse=', ')
  } else {
    y <- x 
  }
  return(y)
}
new_frame <- data.frame(lapply(tibble(df), set_lists_to_chars), stringsAsFactors = F)
write.csv(new_frame, file='test.csv')

或者，您也可以使用 apply 方法将列表转换为字符。无论如何，这会让你得到 csv 中想要的东西。希望。顺便提一下，这个问题很好，@akrun 给出了很好的答案。祝你好运！

Answer 3

好吧，如果你正在尝试为 csv 做准备，一个常见的方法是使用管道将困难部分的全部功劳分给@akrun 但是...

nm1 <- sub("\..*", "", names(df))
nm2 <- names(which(table(nm1) > 1))

df[paste0('combined', seq_along(nm2))] <- lapply(nm2, 
                                                 function(x) 
                                                   apply(df[grep(x, names(df))], 
                                                         1, 
                                                         function(x) str_replace_all(toString(x), 
                                                                                     pattern = ", ", 
                                                                                     replacement = "|")))

> df
   id mon.1 mon.2 mon.2.4.1...1 tue.6  tue    heh   wed wed.01  thu.0234 rating combined1 combined2   combined3
1 HD1     1     a           #ji     1  190    1mn  1890   <NA>   @jksdff      1   1|a|#ji    1| 190     1890|NA
2 HD2     0     b           #ki     2 2345     2a  9002  @ksdf      @sfd      2   0|b|#ki    2|2345  9002|@ksdf
3 HD3     1     c          <NA>     3   41    g78 14341   <NA> @kukg.676      3    1|c|NA    3|  41    14341|NA
4 HD4     4     d           #ui     4   89 asd324   657   <NA>   @jdkfjk      4   4|d|#ui    4|  89      657|NA

自动合并列，其中合并的值在容器中用定界符分隔

Automate columns merging where merged values are separated with a delimiter in the container

r

dataframe

data-cleaning

data-wrangling