Separate Strings Into A Data Frame

I’m working with data that looks like this:

id <- c("673506", "624401", "674764")
bills <- c("sb 1181; ab 573; ab 2697", 
           "sb 1181; ab 573; ab 2697; ab 2448", 
           "sb 292; ab 497")

df <- data.frame(id, bills)
df

How can I transform the data so that the data is long from, the IDs repeat per every corresponding bill separated by a semi-colon?

Such that the data looks like this:

Thank you!

>Solution :

Use separate_rows

library(tidyr)
 separate_rows(df, bills, sep = ";\\s+")

-output

# A tibble: 9 × 2
  id     bills  
  <chr>  <chr>  
1 673506 sb 1181
2 673506 ab 573 
3 673506 ab 2697
4 624401 sb 1181
5 624401 ab 573 
6 624401 ab 2697
7 624401 ab 2448
8 674764 sb 292 
9 674764 ab 497