在dplyr的重命名功能中输入新的列名作为字符串 [英] Enter new column names as string in dplyr's rename function
问题描述
dplyr的重命名功能需要新的列名称作为未引用的变量名传递。但是我有一个函数,其中列名是通过将字符串粘贴到传入的参数来构造的,因此是一个字符串。
dplyr's rename functions require the new column name to be passed in as unquoted variable names. However I have a function where the column name is constructed by pasting a string onto an argument passed in and so is a character string.
例如说我有这个函数
myFunc <- function(df, col){
new <- paste0(col, '_1')
out <- dplyr::rename(df, new = old)
return(out)
}
如果我运行这个
df <- data.frame(a = 1:3, old = 4:6)
myFunc(df, 'x')
我得到
a new
1 1 4
2 2 5
3 3 6
而我想要新列是我构造的字符串的名称('x_1') ,即
Whereas I want the 'new' column to be the name of the string I constructed ('x_1'), i.e.
a x_1
1 1 4
2 2 5
3 3 6
有没有这样做?
推荐答案
我认为这是你正在寻找的。这是@Henrik建议的使用 rename _
,但是参数有一个让我们说有趣的名字:
I think this is what you were looking for. It is the use of rename_
as @Henrik suggested, but the argument has an, lets say, interesting, name:
> myFunc <- function(df, col){
+ new <- paste0(col, '_1')
+ out <- dplyr::rename_(df, .dots=setNames(list(col), new))
+ return(out)
+ }
> myFunc(data.frame(x=c(1,2,3)), "x")
x_1
1 1
2 2
3 3
>
请注意使用 setNames
来使用新值作为列表中的名称。
Note the use of setNames
to use the value of new as name in the list.
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