Avoiding error when using rename in dplyr and column doesn't exist

Question

Is there a clever way to use the rename function in dplyr when in some instances the column to be renamed doesn\'t exist?

For example, I would like the following not to

Answer 1

You can use rename_at() to accomplish this:

mtcars %>%
  rename_at(vars(matches("^missing_var$")), function(x) "foo")

Doesn't return an error if "missing_var" isn't in your data.frame. If you want to replace multiple variables that may or may not exist, you can put the original and new names in a named vector/list, write a short little function to return the new variable name.

customRename <- function(orig_name) {
  renames <- c(
    foo = "OOF",
    bar = "RAB",
    fi = "IF")
  renames[[orig_name]]
}

mtcar %>%
  rename_at(vars(matches("^foo$|^bar$|^fi$")), customRename)