Gドライブに置いたCSVファイルをシートに読み込む

import_csv.gs

function main() {
  var sheet = SpreadsheetApp.getActive().getActiveSheet();
  var file = DriveApp.getFilesByName("test_1.csv").next();
  import_csv(sheet, file);
}

function import_csv(sheet, file, r, c, enc) {
  var table = Utilities.parseCsv(file.getBlob().getDataAsString(enc || "SHIFT_JIS");
  sheet.getRange(r || 1, c || 1, table.length, table[0].length).setValues(table);
}

// おまけ: 命名規則に沿った上で最新ぽいCSVをとってくる
// var file = get_current_csv_file(/test_(\d+)\.csv/, function(m){ return parseInt(m[1], 10) });
function get_current_csv_file(pat, order_of) {
  var current = { order: "" };
  var files = DriveApp.getFilesByType("text/csv");
  while (files.hasNext()) {
    var file = files.next();    
    var m = file.getName().match(pat);
    if (m) {
      var order = order_of(m);
      if (order > current.order) {
        current.order = order;
        current.file  = file;
      }
    }
  }
  return current.file;
}