R/read_mbox.R

In mboxr: Reading, Extracting, and Converting an Mbox File into a Tibble

#' read_mbox
#' @title Converting an mbox file into a tibble data_frame.

#' @aliases read_mbox
#' @keywords read_mbox

#' @description Use this function for importing and converting an mbox file into a tibble object.
#' @export read_mbox
#' @param mbox Input mbox file.
#' @param file Output RDS file if you want to save. The default is NULL, which is not saving the output as a file.

#' @details
#' See example below.

#' @return Tibble object for the input mbox file will be returned.

#' @examples
#' \donttest{
#' # Changing working directory to temp for the demonstration purpose only.
#' setwd(tempdir())
#' library(mboxr)
#' # Feeding an mbox file through read_mbox function:
#' test <- system.file("extdata", "test1.mbox", package = "mboxr")
#' data <- read_mbox(mbox = test, file = "output.rds")
#' # Now you can use the imported file as a tibble.
#' str(data)
#' }

#' @author JooYoung Seo, \email{jooyoung@psu.edu}
#' @author Soyoung Choi, \email{sxc940@psu.edu}

#' @references \url{https://en.wikipedia.org/wiki/Mbox}
#' @references \url{https://docs.python.org/3/library/mailbox.html}
#' @references \url{https://www.anaconda.com/download/}

read_mbox <- 
function(mbox = NULL, file = NULL) {   # Function starts:

	if(is.null(mbox) || tools::file_ext(mbox) != "mbox") {
		stop("Please pass an mbox file for the first argument.")
	}

	envnm <- 'mboxr'

	tryCatch({
		if (!(envnm %in% reticulate::conda_list()$name)) {
			reticulate::conda_create(envnm, packages = c("python=3.7.3", "pandas"), conda = "auto")
		}
	},
	error = function(e) {
		stop("Need to install Anaconda from https://www.anaconda.com/download/.")
	},
	finally = {
		reticulate::use_condaenv(envnm, required = TRUE)
			if (!reticulate::py_module_available("pandas")) {
				reticulate::conda_install(envnm, packages = c('pandas'))
			}

			if (!reticulate::py_module_available("mailbox")) {
				reticulate::conda_install(envnm, packages = c('mailbox'))
			}

			if (!reticulate::py_module_available("email")) {
				reticulate::conda_install(envnm, packages = c('email'))
			}
	})

	df <- reticulate::import_from_path(module = "mboxR", path = system.file("python", package="mboxr"), convert = TRUE)$mbox_df(mbox)
	df <- dplyr::na_if(tibble::tibble(date = as.character(df$date), message_ID = as.character(df$message_ID), in_reply_to = as.character(df$in_reply_to), references = as.character(df$references), from = as.character(df$from), to = as.character(df$to), cc = as.character(df$cc), subject = as.character(df$subject), content = as.character(df$content)), "NULL") %>%
	dplyr::mutate(date = lubridate::as_datetime(df$date))
	df <- df %>%
	dplyr::mutate(num_discussants = tidyr::replace_na((1+stringr::str_count(df$references, "@")), 1)) %>%
	dplyr::mutate(weekday = lubridate::wday(df$date, label = TRUE)) %>%
	dplyr::arrange(date)
	
	if(!is.null(file)) {
		fileExt <- tolower(tools::file_ext(file))
		if(fileExt == "") {
			saveRDS(df, file = paste0(file, ".rds"))
		} else if(fileExt == "rds") {
			saveRDS(df, file = file)
		} else {
			warning("Something is wrong with your output file name. Currently only 'RDS' format is supported.")
		}
	}
	return(df)

}   # Function ends.