Evan, List names are less easy than data.frame column names so try this:
> test <- list(a=3,b=5,c=11) > colnames(test) NULL > colnames(as.data.frame(test)) [1] "a" "b" "c" But note an entry with no name has one made up for it. > test2 <- list(a=3,b=5, 666, c=11) > colnames(data.frame(test2)) [1] "a" "b" "X666" "c" But that may be overkill as simply converting to a vector if ALL parts are of the same type will work too: > names(as.vector(test)) [1] "a" "b" "c" To get one at a time: > names(as.vector(test))[1] [1] "a" You can do it even simple by looking at the attributes of your list: > attributes(test) $names [1] "a" "b" "c" > attributes(test)$names [1] "a" "b" "c" > attributes(test)$names[3] [1] "c" -----Original Message----- From: R-help <r-help-boun...@r-project.org> On Behalf Of Evan Cooch Sent: Thursday, May 25, 2023 1:30 PM To: r-help@r-project.org Subject: [R] extract parts of a list before symbol Suppose I have the following list: test <- list(a=3,b=5,c=11) I'm trying to figure out how to extract the characters to the left of the equal sign (i.e., I want to extract a list of the variable names, a, b and c. I've tried the permutations I know of involving sub - things like sub("\\=.*", "", test), but no matter what I try, sub keeps returning (3, 5, 11). In other words, even though I'm trying to extract the 'stuff' before the = sign, I seem to be successful only at grabbing the stuff after the equal sign. Pointers to the obvious fix? Thanks... ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.