How to Use Dplyr::Rename_At Together with “Starts_with” in a Function

Question

library(tidyverse)

Using the sample data below, I have two dataframes - Df1 and Df2. I'm attempting to create a simple function that selects columns by string - in this case columns in both dataframes that start with "Person" as well as all columns that contain "Phone".

Next, I would like to rename the "Person" column in both dataframes to "Id".

However, I'm having trouble getting the rename function to work correctly.

Here is a first attempt...

Funs<-function(Df){
Df%>%select(starts_with("Person"),contains("Phone"))%>%
rename_at(vars(starts_with("Person"),"Id"))
}

Below are some other variations of "rename" that I tried, but didn't work...

rename_at(vars(starts_with("Person"),funs("Id"=.)))

rename("Id"=names(.)[1])

How should I correct this? I tried to find similar questions on this site since it seems simple enough, but I couldn't find anything that works...

Sample Data:

`Person #`<-c(199,148,148,145,177,165,144,121,188,188,188,111)
`Phone #1`<-c(6532881717,6572231223,6541132112,6457886543,6548887777,7372222222,6451123425,6783450101,7890986543,6785554444,8764443344,6453348736)
`Phone #2`<-c(NA,NA,NA,NA,NA,7372222222,NA,NA,NA,6785554444,NA,NA)
Animals<-c("Cat","Dog","Elephant","Giraffe","Bird","Snake","Skunk","Raccoon","Moose","Turtle","Beaver","Porcupine")

Df1<-data.frame(`Person #`,`Phone #1`,`Phone #2`, Animals)


`Person ID #`<-c(199,148,142,145,177,165,144,121,182,109,188,111)
`Phone s 1`<-c(6532881717,6572231223,6541132112,6457886543,6548887777,7372222222,6451123425,6783450101,7890986543,6785554400,8764443344,6453348736)
`Phone s 2`<-c(NA,NA,NA,NA,NA,7372222222,NA,NA,NA,6785554444,NA,NA)
Animals<-c("Cat","Dog","Elephant","Giraffe","Bird","Snake","Skunk","Raccoon","Moose","Turtle","Beaver","Porcupine")

Df2<-data.frame(`Person ID #`,`Phone s 1`,`Phone s 2`, Animals)

Answer 1

These two options work, though seems very fragile to rename in this way; It only works if you have exactly one column that meets the condition, ie starts_with('Person') :

Df1 %>% rename_at(vars(starts_with('Person')), ~ 'ID')

Df1 %>% rename_at(1, ~ 'ID')

Both give:

#    ID   Phone..1   Phone..2   Animals
#1  199 6532881717         NA       Cat
#2  148 6572231223         NA       Dog
#3  148 6541132112         NA  Elephant
#  ...

Or use funs :

Df1 %>% rename_at(vars(starts_with("Person")),funs(function(.) 'ID'))

Answer 2

The above did not work for me. This example does run:

tribble(
  ~col_name_1, ~col_name_2_foo, ~col_name_3_foo,
  "a", 1, 3,
  "b", 2, 2,
  "c", 3, 1
) %>%
rename_at(
  vars(ends_with("_foo")), function(x) { toupper(x) }
)

# A tibble: 3 x 3
  col_name_1 COL_NAME_2_FOO COL_NAME_3_FOO
  <chr>               <dbl>          <dbl>
1 a                       1              3
2 b                       2              2
3 c                       3              1

rename_at(vars(ends_with("_foo")), toupper) also works if the function you want to use is already defined.