def stringToLek(red):
    lek = {}
    deo = red.strip().split("|")
    lek["ser_br"] = int(deo[0])
    lek["fab_naziv"] = deo[1]
    lek["gen_naziv"] = deo[2]
    lek["kol_leka"] = int(deo[3])
    lek["c_leka"] = float(deo[4])
    return lek
def  lekToString(lek):
    return '|'.join([lek['ser_br'], lek['fab_naziv'], lek['gen_naziv'], lek['c_leka'], lek['kol_leka']])

TypeError: sequence item 0: expected str instance, int found