copy everything after a string into a different column in R

Question

I have some columns in a data frame that look like this:

df <- data.frame(act=c("DEC S/N, de 21/06/2006",
                        "DEC S/N, de 05/06/2006",
                         "DEC S/N, de 21/06/2006; MP 542, de 12/08/2011; LEI 12.678, de 25/06/2012"), adj=NA)

I would like to copy everything after the first ; (MP 542, de 12/08/2011; LEI 12.678, de 25/06/2012) in the column 'act', into the column 'adj'. Ideally, removing the space that would be left at the star of the cut-off string. All other cells, this is, where the strings in column 'act' do not have a ; should be left NA in column 'adj'.

Answer 1

Using stringr::str_extract -

df$adj <- stringr::str_extract(df$act, '(?<=;\\s)(.*)')
df$adj
#[1] NA   NA    "MP 542, de 12/08/2011; LEI 12.678, de 25/06/2012"

Answer 2

df %>%
  extract(act, 'adj', '; (.*)', remove = FALSE)

or even try:

df %>%
  separate(act, c('act1', 'adj'), '; ', 
           extra = 'merge', fill = 'right', remove = FALSE)