flatten nested lists from jsonLITE (e.g. for CSV export) in R. This will join the nested lists with a semicolon separator.

flattenjsonLITE.R

f <- function(df) {

    for (col in names(df)) {
        if (is.list(df[[col]])) {
            i <- 1
            for (row in df[[col]]) {

                df[[col]][i] <- paste(row, collapse = '; ')
                i <- i + 1
            }
            df[[col]] <- unlist(df[[col]])
        }
    }
return (df)
}