使用另一列的值重命名列

Question

我有一组列名如下

  "fb_metrics.3.name"                                     
  "fb_metrics.3.period"                                   
  "fb_metrics.3.values.0.value.share"                     
  "fb_metrics.3.values.0.value.like"                      
  "fb_metrics.3.values.0.value.comment"                   
  "fb_metrics.3.title"                                    
  "fb_metrics.3.description"

名称和句点各有一个唯一值。例如

> df[,"fb_metrics.3.name"]
[1] post_storytellers_by_action_type
Levels: post_storytellers_by_action_type

> df[, "fb_metrics.3.period"]
[1] lifetime
Levels: lifetime

我想像这样重命名第 3、4、5 列

[1] "post_storytellers_by_action_type.lifetime.share"  
[2] "post_storytellers_by_action_type.lifetime.like"   
[3] "post_storytellers_by_action_type.lifetime.comment"

我已经像这样管理了替换钻头

i=3
new_column_name <- paste(as.character(df[1,paste("fb_metrics.",
                    i,".name", sep = "")]),as.character(df[1,paste("fb_metrics.",
                    i,".period", sep = "")]), sep = "." )

sub(pattern = ".*value",replacement = new_column_name,x = colnames(df[,
        grep(paste("fb_metrics.",i,".values.*",sep = ""), column_names)]))

并且我提取了要替换的列，这样

column_names <- colnames(df)

list_of_columns <- colnames(df[,grep("fb_metrics.3.values.*", column_names)])

我的问题是如何用我刚刚创建的列名重命名提取的列？另外，有没有更简单的方法呢？

编辑：

好的，我这样改名了

library(data.table)
setnames(df, old = list_of_columns, new = sub(pattern = ".*value",replacement = new_column_name,x = colnames(df[,grep(paste("fb_metrics.",i,".values.*",sep = ""), column_names)])))

但是有没有更简单的方法来完成整个过程？

Answer 1

当面临 complex/multiple 替换时，您可以通过创建自定义函数来简化流程使用不同的输入参数并按顺序应用它以达到所需的列名称结构。

输入数据：

DF1 = data.frame(fb_metrics.3.name="post_storytellers_by_action_type",fb_metrics.3.period="lifetime",fb_metrics.3.values.0.value.share=1:5,fb_metrics.3.values.0.value.like=1:5,
fb_metrics.3.values.0.value.comment=1:5,stringsAsFactors=FALSE)


DF1
#                 fb_metrics.3.name fb_metrics.3.period fb_metrics.3.values.0.value.share
#1 post_storytellers_by_action_type            lifetime                                 1
#2 post_storytellers_by_action_type            lifetime                                 2
#3 post_storytellers_by_action_type            lifetime                                 3
#4 post_storytellers_by_action_type            lifetime                                 4
#5 post_storytellers_by_action_type            lifetime                                 5

#  fb_metrics.3.values.0.value.like fb_metrics.3.values.0.value.comment
#1                                1                                   1
#2                                2                                   2
#3                                3                                   3
#4                                4                                   4
#5                                5                                   5

自定义函数：

#Custom function to aid replacements

 fn_modify_str = function(pattern="a",replacement="str",suffix=".",inputString="abcd") {

 gsub(pattern,paste0(replacement,suffix),inputString)

 }

参数：

 inputColumn1 = "^fb_metrics.3.name$"
 inputColumn2 = "^fb_metrics.3.period$"

 replacePattern1 = "fb_metrics.3.values.0[.]"
 replacePattern2 = "value"

 uniqValue1 = unique(DF1[,grep(inputColumn1,colnames(DF1))])

uniqValue1
#[1] "post_storytellers_by_action_type"

 uniqValue2 = unique(DF1[,grep(inputColumn2,colnames(DF1))])

uniqValue2
#[1] "lifetime"

替换：

#apply replacements using custom function  sequentially for both patterns

strPart1 =  fn_modify_str(pattern=replacePattern1,replacement = uniqValue1,suffix=".",inputString = colnames(DF3))

strPart2 =  fn_modify_str(pattern=replacePattern2,replacement = uniqValue2,suffix="",inputString = strPart1)


#you can rename columns in the same dataset by just simple assignment
#colnames(DF1) = strPart2

#OR, you can create a backup dataset and rename the columns in the new DF
DF2 = DF1

colnames(DF2) = strPart2

输出：

DF2
#                 fb_metrics.3.name fb_metrics.3.period post_storytellers_by_action_type.lifetime.share
#1 post_storytellers_by_action_type            lifetime                                               1
#2 post_storytellers_by_action_type            lifetime                                               2
#3 post_storytellers_by_action_type            lifetime                                               3
#4 post_storytellers_by_action_type            lifetime                                               4
#5 post_storytellers_by_action_type            lifetime                                               5
#  post_storytellers_by_action_type.lifetime.like post_storytellers_by_action_type.lifetime.comment
#1                                              1                                                 1
#2                                              2                                                 2
#3                                              3                                                 3
#4                                              4                                                 4
#5                                              5                                                 5

使用另一列的值重命名列

Renaming columns with a value from another column

r

renaming

dataframe