strsplit with vertical bar (pipe)

问题

Here,

> r<-c("AAandBB", "BBandCC")
> strsplit(as.character(r),'and')
[[1]]
[1] "AA" "BB"

[[2]]
[1] "BB" "CC"

Working well, but

> r<-c("AA|andBB", "BB|andCC")
> strsplit(as.character(r),'|and')
[[1]]
[1] "A" "A" "|" ""  "B" "B"

[[2]]
[1] "B" "B" "|" ""  "C" "C"

Here, the answer is not correct. How to get "AA" and "BB", when I use '|and'?
Thanks in advance.

回答1:

As you can read on ?strsplit, the argument split in function strsplit is a regular expression. Hence either you need to escape the vertical bar (it is a special character)

strsplit(r,split='\\|and')

or you can choose fixed=TRUE to indicate that split is not a regular expression

strsplit(r,split='|and',fixed=TRUE)

来源：https://stackoverflow.com/questions/23193219/strsplit-with-vertical-bar-pipe