重命名数据框列的列表以模拟连接的后缀 [英] rename list of dataframe columns to mimic joined suffixes

问题描述

我有一个数据帧列表:

dd <- list()

dd$data <- list(
  ONE = data.frame(inAll = c(1.1,1.2,1.3), inAll_2 = c(1.4,1.5,1.6)),
  TWO = data.frame(inAll = c(2.1,2.2,2.3), inAll_2 = c(2.4,2.5,2.6)),
  THREE = data.frame(inAll = c(3.1,3.2,3.3), inAll_2 = c(3.4,3.5,3.6)),
  FOUR = data.frame(inAll = c(4.1,4.2,4.3), inAll_2 = c(4.4,4.5,4.6)),
  FIVE = data.frame(inAll = c(5.1,5.2,5.3), inAll_2 = c(5.4,5.5,5.6)),
  SIX = data.frame(inAll = c(6.1,6.2,6.3), inAll_2 = c(6.4,6.5,6.6))
)

然后使用后缀减少这些数据框

And then reduce those dataframes using suffixes

reduce(dd$data, full_join, by = "inAll", suffix = c("_x", "_y"))

我想要的输出是

map(dd$data, list())

但是我希望名称与简化数据集中的后缀相同.

BUT I want the names to be the same as the suffixes in the reduced dataset.

如何扩展此地图功能，以便重命名列表中的列以反映简化的名称?

How do I expand on this map function so that I rename the columns in the list to reflect the reduced names?

[我尝试查看此连接的源代码！]，看起来所有匹配但未连接到列的都是:

[I tried looking at the join source code for this!] and it looks like all matching but not joined on columns are:

• 先给出_x后缀_y
• 以_x_x和_y_y继续，以此类推
• 如果带有重复列无后缀的列表项数最后一次

请注意，在我的示例中，这些数据帧通常具有其他列，并且这些列并不总是具有相同的顺序，因此我想避免任何易碎的事情，例如按索引进行匹配！

new_names <- function(df) {
  # logic about new suffixes somehow
  map(df,list())
}

所需的输出

看起来像这样的列表:

Desired Output

A list that looks like this:

dd$data2 <- list(
  ONE = data.frame(inAll = c(1.1,1.2,1.3), inAll_2_x = c(1.4,1.5,1.6)),
  TWO = data.frame(inAll = c(2.1,2.2,2.3), inAll_2_y = c(2.4,2.5,2.6)),
  THREE = data.frame(inAll = c(3.1,3.2,3.3), inAll_2_x_x = c(3.4,3.5,3.6)),
  FOUR = data.frame(inAll = c(4.1,4.2,4.3), inAll_2_y_y = c(4.4,4.5,4.6)),
  FIVE = data.frame(inAll = c(5.1,5.2,5.3), inAll_2_x_x_x = c(5.4,5.5,5.6)),
  SIX = data.frame(inAll = c(6.1,6.2,6.3), inAll_2_y_y_y = c(6.4,6.5,6.6))
)

推荐答案

我们可以使用 strrep (来自 base R )为'x'创建重复的字符串，'y'， rep 对其进行匹配，并在 list 列上循环显示 map2 和 rename_at 第二列，粘贴( str_c )后缀

We can create a repeated character string with strrep (from base R) for 'x', 'y', replicate it, loop over the list column with map2 and rename_at the 2nd column by pasteing (str_c) the suffix passed

library(dplyr)
library(purrr)
library(stringr)
n <- ceiling(length(dd$data)/2)
map2(dd$data,  strrep(rep(c('_x', '_y'), n), rep(seq_len(n), each = 2)), ~
             {nm <- .y
               .x %>% 
                 rename_at(vars(inAll_2), ~ str_c(., nm))
     })
#$ONE
#  inAll inAll_2_x
#1   1.1       1.4
#2   1.2       1.5
#3   1.3       1.6

#$TWO
#  inAll inAll_2_y
#1   2.1       2.4
#2   2.2       2.5
#3   2.3       2.6

#$THREE
#  inAll inAll_2_x_x
#1   3.1         3.4
#2   3.2         3.5
#3   3.3         3.6

#$FOUR
#  inAll inAll_2_y_y
#1   4.1         4.4
#2   4.2         4.5
#3   4.3         4.6

#$FIVE
#  inAll inAll_2_x_x_x
#1   5.1           5.4
#2   5.2           5.5
#3   5.3           5.6

#$SIX
#  inAll inAll_2_y_y_y
#1   6.1           6.4
#2   6.2           6.5
#3   6.3           6.6

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