Subset a dataframe according to matches between dataframe column and separate character vector in R -

i want use chacracter vector to:

1. find rows in dataframe contain single or greater matches vector in comma delimited list within column of dataframe
2. subset dataframe retaining rows matches

example data

look<-c("id1", "id2", "id5", "id9") df<-data.frame(var1=1:10, var2=3:12, var3=rep(c("","id1,id3","id1,id9","",""))) df    var1 var2    var3 1     1    3         2     2    4 id1,id3 3     3    5 id1,id9 4     4    6         5     5    7         6     6    8         7     7    9 id1,id3 8     8   10 id1,id9 9     9   11         10   10   12  

where output like:

    var1 var2    var3 1    2    4 id1,id3 2    3    5 id1,id9 3    7    9 id1,id3 4    8   10 id1,id9 

the match between var3 column greater 1 value look vector.

is there base r solution doesn't involve using strsplit on var3 column?

1) create appropriate regular expression , perform grep. requested not use packages , not use strsplit:

subset(df, grepl(paste0("\\b", paste(look, collapse = "|"), "\\b"), var3)) 

giving:

  var1 var2    var3 2    2    4 id1,id3 3    3    5 id1,id9 7    7    9 id1,id3 8    8   10 id1,id9 

1a) depending on precisely var3 , look contain may possible shorten (but less general longer 1 above -- example id1 match id11 if used prior solution not have problem):

subset(df, grepl(paste(look, collapse = "|"), var3)) 

2) if willing relax strsplit requirement still not use packages:

subset(df, sapply(strsplit(as.character(var3), ","), function(x) any(x %in% look)))