Split data frame string column into multiple columns
Another option is to use the new tidyr package.
library(dplyr)library(tidyr)before <- data.frame( attr = c(1, 30 ,4 ,6 ), type = c('foo_and_bar', 'foo_and_bar_2'))before %>% separate(type, c("foo", "bar"), "_and_")## attr foo bar## 1 1 foo bar## 2 30 foo bar_2## 3 4 foo bar## 4 6 foo bar_2
5 years later adding the obligatory data.table solution
library(data.table) ## v 1.9.6+ setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_")]before# attr type type1 type2# 1: 1 foo_and_bar foo bar# 2: 30 foo_and_bar_2 foo bar_2# 3: 4 foo_and_bar foo bar# 4: 6 foo_and_bar_2 foo bar_2We could also both make sure that the resulting columns will have correct types and improve performance by adding type.convert and fixed arguments (since "_and_" isn't really a regex)
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_", type.convert = TRUE, fixed = TRUE)]