code: def _create_translation_file(feature_folder,
                               dataset_name,
                               translation,
                               formula_id2index):
      
      translationfilename = "%s/translation-%s.csv" % (feature_folder,
                                                       dataset_name)
      with open(translationfilename, "w") as f:
          f.write("index,raw_data_id,latex,formula_id\n")
          for el in translation:
              f.write("%i,%i,%s,%i\n" % (formula_id2index[el[2]],
                                         el[0], el[1], el[2]))
docs: Write a loop-up file that contains the direct (record-wise) lookup
      information.
  
      Parameters
      ----------
      feature_folder :
          Path to the feature files.
      dataset_name :
          'traindata', 'validdata' or 'testdata'.
      translation : list of triples
          (raw data id, formula in latex, formula id)