how to remove a subset from a column within square brackets in r

问题

I've a column with has multiple strings in square brackets something like this [asdf] [ffgg][ asdf asdf asdf] sdfsgsfbsfg and I've to extract [asdf asdf asdf] it may have only one string like [asdf] or two. Please help

回答1:

We can use str_extract

library(stringr)
str_extract(str1, "\\[(\\w+\\s+){2,}\\w+\\]")    
#[1] "[asdf asdf asdf]"

Or may be

str_extract(str1, "\\[(\\w+\\s+)\\1+[^]]+\\]")
#[1] "[asdf asdf asdf]"

data

str1 <- "[asdf] [ffgg][asdf asdf asdf] sdfsgsfbsfg"

来源：https://stackoverflow.com/questions/44093818/how-to-remove-a-subset-from-a-column-within-square-brackets-in-r