R/batch_csv_dump.R

In CT-Data-Haven/cwi: Prep for DataHaven's Community Wellbeing Index

#' Write a list of data frames to CSV and keep it movin'
#'
#' This function takes either a list of data frames, or a data frame and a column to split by, and writes them all to CSV files. It then returns the list of data frames, optionally row-binded back together. It fits neatly in the middle of a longer piped workflow.
#' @param data A data frame or a list of data frames
#' @param split_by Bare column name of variable to split by. If `data` is a list, this is unnecessary and will be ignored.
#' @param path String giving a path at which to save files; defaults to current working directory.
#' @param base_name Optional string to be prepended to all file names.
#' @param bind Logical: whether to row-bind list of data frames into a single data frame. Defaults `FALSE`, in which case a list of data frames is returned.
#' @param verbose Logical: whether to print files' paths and names as they're written. Defaults `TRUE`.
#' @param ... Additional arguments to pass to `utils::write.csv`, such as `na` or `col.names`.
#' @return Either a list of data frames (in case of `bind = FALSE`) or a single data frame (in case of `bind = TRUE`).
#'
#' @export
batch_csv_dump <- function(data, split_by, path = ".", base_name = NULL, bind = FALSE, verbose = TRUE, ...) {
  # if data is a data frame, split it. Otherwise treat as list
  if (is.data.frame(data) & missing(split_by)) {
    cli::cli_abort("Please supply either a list of data frames, or a column to split data by.")
  }
  if (!dir.exists(path)) cli::cli_abort("Path {.file {path}} does not exist.")
  if (is.data.frame(data)) {
    data_list <- split(data, dplyr::select(data, {{ split_by }}))
  } else {
    data_list <- data
  }

  cli::cli_ul()
  out <- purrr::iwalk(data_list, function(df, name) {
    filename <- stringr::str_c(base_name, name, sep = "_")
    filename <- stringr::str_replace_all(filename, "\\s+", "_")
    filename <- paste(filename, "csv", sep = ".")
    filepath <- file.path(path, filename)
    utils::write.csv(df, file = filepath, row.names = FALSE, ...)
    if (verbose) cli::cli_li("Writing {.file {filepath}}")
  })
  cli::cli_end()
  if (bind) {
    out <- dplyr::bind_rows(out)
  }
  out
}