def get_param_stats_num(param_file, observed_df):
    """
    Get number of parameters and statistics from simulation.
    :param param_file: param file that was used to run the simulations.
    :param observed_df: dataframe of parameter and summary stats from one simulation. 
    :return: param_num: number of parameters
    :return: stats_num: number of stats
    """

    param_num = sum(1 for line in open(param_file))
    stats_num = len(observed_df.columns) - param_num
    return [param_num, stats_num]