Export errors unnecessarily if passed x is a list of length one.

[cha-petersumm]

It would be neater if the export function worked when passed a dataframe list with length = 1, regardless of the export format.

An error would still occur if length > 1 and the export format didn't support it.

This would avoid the need for this sort of code:

if (length(data_list) > 1 | info$export_function == "writexl::write_xlsx")
export(data_list, output_filename)
else
export(data_list[[1]], output_filename)

[cha-petersumm]

I haven't tested this, but I think it can be done in export.R by replacing

if (!is.data.frame(x) && !format %in% c("xlsx", "html", "rdata", "rds", "json", "qs", "fods", "ods")) {
stop("'x' is not a data.frame or matrix", call. = FALSE)
}

with

if (!is.data.frame(x) && !format %in% c("xlsx", "html", "rdata", "rds", "json", "qs", "fods", "ods")) {
if (is.list(x) && (length(x) == 1) && is.data.frame(x[[1]]))
x <- x[[1]]
else
stop("'x' is not a data.frame, matrix or list of exactly one data.frame", call. = FALSE)
}

[chainsawriot]

@cha-petersumm Thank you for reporting and suggesting a solution.

There will be an update. But I will put

if (is.list(x) && (length(x) == 1) && is.data.frame(x[[1]])) {
    x <- x[[1]]
}

in an outer loop.

[cha-petersumm]

No problem.

You want to avoid doing this for file formats where it's not necessary. In particular, for Excel files, exporting a list preserves the sheet names whereas converting a list of length = 1 to the first element and then exporting will lose them.

[chainsawriot]

Please install the latest version

install.packages("rio", repos = "https://gesistsa.r-universe.dev")

And there are tests for preserving sheet names when length(x) == 1.

[cha-petersumm]

Great work! Thanks.

[cha-petersumm]

Also, in case it's ever useful to you, this is my example of where it was used. It's written to de-identify files containing patient data:

cat(---
title: "deidentify patient data"
author: "Peter Summers"
date: "r Sys.Date()"
output: html_document

knitr::opts_chunk$set(echo = TRUE)

library(tidyverse)
library(rio)
library(tools)
library(openssl)

Deidentify the chosen files.

password <- "Put a project-specific password here."

input_filename_list <- choose.files()

for (input_filename in input_filename_list) {

  output_filename <- paste0(file_path_sans_ext(input_filename)," - deidentified.", file_ext(input_filename))
  
  info <- get_info(input_filename)
  
  data_list <- import_list(input_filename, format=info$format)
  
  # Process multiple data frames if there is more than one, e.g. from a multi-sheet Excel file.
  for (dataset_number in 1:length(data_list)) {
    for (column_name in c("MRN","PAT_ID","CSN","LOG_ID","ORDER_ID")) {
      if (!is.null(data_list[[dataset_number]][[column_name]])) 
        data_list[[dataset_number]][[column_name]] <- md5(as.character(data_list[[dataset_number]][[column_name]]), key=password)
    }
  }
  
# Uncomment the three lines below if not using a version of rio with fix #385.
  # if (length(data_list) > 1 | info$export_function == "writexl::write_xlsx")
    export(data_list, output_filename, format=info$format)
  # else
  #   export(data_list[[1]], output_filename, format=info$format)
}