def get_cols(tname):
    """ Takes the name of a neuropsych test and returns a tupple of two lists.
    The first list has the headers of the metrics of
    interest (columns in the test's  score table).
    The second list has the names to be given to these metrics
    in the final table of neuropsych scores outputed by this script.
    Parameter:
    ----------
    tname: string (name of a neuropsych test)

    Return:
    ----------
    a tupple associated with the test's name (key in the switcher dictionnary);
    the tupple contains two lists of strings of equal length
    """
    switcher = {
        'alpha_span': (['71233_rappel_alpha_item_reussis', '71233_rappel_alpha_pourcentage'], ['aspan_recall_correct_items', 'aspan_recall_percentage']),
        'boston_naming_test': (['57463_boston_score_correcte_spontanee', '57463_boston_score_total'],['boston_correct_spontaneous', 'boston_total']),
        'easy_object_decision': (['45463_score'], ['easy_object_decision_score']),
        'echelle_depression_geriatrique': (['    d.70664_score'], ['gds_score']),
        'echelle_hachinski': (['86588_score'],['hachinski_score']),
        'evaluation_demence_clinique': (['34013_cdr_sb'], ['cdr_sb']),
        'fluence_verbale_animaux': (['    18057_score_reponse_correcte'], ['verb_flu_correct_responses']),
        'histoire_logique_wechsler_rappel_immediat': (['24918_score_hist_rappel_immediat'],['log_story_immediate_recall']),
        'histoire_logique_wechsler_rappel_differe': (['40801_score_hist_rappel_differe'],['log_story_delayed_recall']),
        'memoria': (['18087_score_libre_correcte', '18087_score_indice_correcte'],['memoria_free_correct', 'memoria_indice_correct']),
        'moca': (['12783_score', '12783_score_scolarite'], ['moca_score', 'moca_score_schooling']),
        'prenom_visage': (['33288_score_rappel_immediat', '33288_score_rappel_differe'], ['name_face_immediate_recall', 'name_face_delayed_recall']),
        'ravlt': (['86932_mots_justes_essai_1', '86932_mots_justes_essai_total1', '86932_mots_justes_rappel_diff_a', '86932_score_total_reconnaissance'], ['RAVLT_trial1', 'RAVLT_total', 'RAVLT_delRecall', 'RAVLT_recognition']),
        'test_enveloppe': (['75344_score_memoire_prospective', '75344_score_memoire_retrospective'], ['env_prospective_memory', 'env_retrospective_memory']),
        'tmmse': (['80604_score_total'],['mmse_total']),
        'trail_making_test': (['44695_temps_trailA', '44695_temps_trailB', '44695_ratio_trailB_trailA'],['trailA_time', 'trailB_time', 'trailB_trailA_ratio']),
        'stroop': (['77180_cond3_temps_total', '77180_cond3_total_erreurs_corrigees', '77180_cond3_total_erreurs_non_corrigees', '77180_cond4_temps_total', '77180_cond4_total_erreurs_corrigees', '77180_cond4_total_erreurs_non_corrigees'],['Stroop_cond3_time', 'Stroop_cond3_corr_errors', 'Stroop_cond3_nonCorr_errors', 'Stroop_cond4_time', 'Stroop_cond4_corr_errors', 'Stroop_cond4_nonCorr_errors']),
        'vocabulaire': (['87625_score'],['WAIS_vocabulary']),
        'wais_digit_symbol':(['12321_resultat_brut'],['WAIS_digit_symbol_total'])
    }
    return switcher.get(tname, ([], []))