为 r 中的 or 语句折叠向量中的字符串三次

Question

I have a vector with multiple strings

strings <- c("CD4","CD8A")

and I'd like to output an OR statement to be passed to grep like so

"CD4-|-CD4-|-CD4$|CD8A-|-CD8A-|-CD8A$"

and so on for each element in the vector..

basically I'm trying to find an exact word in a string that has three dashes in it, (I don't want grep(CD4, ..) to return strings with CD40). This is how I thought of doing it but I'm open to other suggestions

part of my data.frame looks like this:

Genes <- as.data.frame(c("CD4-MyD88-IL27RA", "IL2RG-CD4-GHR","MyD88-CD8B-EPOR", "CD8A-IL3RA-CSF3R", "ICOS-CD40-LMP1"))
colnames(Genes) <- "Genes"

Answer 1

Here is a one-liner...

Genes$Genes[grep(paste0("\\b",strings,"\\b",collapse="|"),Genes$Genes)]

[1] "CD4-MyD88-IL27RA" "IL2RG-CD4-GHR"    "CD8A-IL3RA-CSF3R"

It uses word-boundary markers \\\\b to make sure that it matches complete substrings (as the - does not count as part of a word).

Answer 2

I don't know if I understood. If I got it, the following command will return what you want

stringr::str_split(Genes$Genes, pattern = '-') %>% 
  purrr::map(
    function(data) {
      data[stringr::str_which(data, pattern = '^CD')]
    }
  )  %>% unlist