Convert data.frame columns from factors to characters

Question

I have a data frame. Let\'s call him bob:

> head(bob)
                 phenotype                         exclusion
GSM399350 3- 4- 8- 25- 44+         


        

Answer 1

To replace only factors:

i <- sapply(bob, is.factor)
bob[i] <- lapply(bob[i], as.character)

In package dplyr in version 0.5.0 new function mutate_if was introduced:

library(dplyr)
bob %>% mutate_if(is.factor, as.character) -> bob

...and in version 1.0.0 was replaced by across:

library(dplyr)
bob %>% mutate(across(where(is.factor), as.character)) -> bob

Package purrr from RStudio gives another alternative:

library(purrr)
bob %>% modify_if(is.factor, as.character) -> bob