Returns a uniform timestamp with parameter values for file identification

def timestamp(num_params, p_levels, k_choices, N):
    """
    Returns a uniform timestamp with parameter values for file identification
    """
    string = "_v%s_l%s_gs%s_k%s_N%s_%s.txt" % (num_params,
                                               p_levels,
                                               k_choices,
                                               N,
                                               dt.strftime(dt.now(),
                                                           "%d%m%y%H%M%S"))
    return string