R/dataframes.r

In lukehannan/lumisc: Miscellaneous Functions to Help With Data Analysis

#' Write Dataframes
#'
#' Write a list of rectangular dataframes to a single csv keeping column names, and appending a single space between
#' dataframes.
#'
#' This function never writes row names to the csv file.
#'
#' @name write_df
#' @param list The list of dataframes to append to a single csv file.
#' @param file File name of the final csv.
#' @param overwrite Boolean value, if true will always overwrite file even if it exists.
#' @param ... Additional options passed to the write.table command.
#' @export
write_df = function(list, file, overwrite = TRUE, ...) {
  for (i in seq_len(length(list))) {
    # on the first write we check if overwrite is true and overwrite the file if it exists
    if (i == 1 & overwrite == TRUE) {
      utils::write.table(list[[i]], file, row.names = FALSE, col.names = TRUE, sep = ",", append = FALSE, ...)
      utils::write.table("", file, row.names = FALSE, col.names = FALSE, sep = ",", append = TRUE, ...)
      next
    }

    if (i == length(list)) {
      utils::write.table(list[[i]], file, row.names = FALSE, col.names = TRUE, sep = ",", append = TRUE, ...)
      next
    }

    utils::write.table(list[[i]], file, row.names = FALSE, col.names = TRUE, sep = ",", append = TRUE, ...)
    utils::write.table("", file, row.names = FALSE, col.names = FALSE, sep = ",", append = TRUE, ...)
  }
}