def get_df_between_date(data_df, date_frm, date_to):
    """
    该函数仅用于 return_risk_analysis 中计算使用
    :param data_df:
    :param date_frm:
    :param date_to:
    :return:
    """
    if date_frm is not None and date_to is not None:
        new_data_df = data_df[(data_df.Date >= date_frm) & (data_df.Date <=
            date_to)]
    elif date_frm is not None:
        new_data_df = data_df[data_df.Date >= date_frm]
    elif date_to is not None:
        new_data_df = data_df[data_df.Date <= date_to]
    else:
        new_data_df = data_df
    new_data_df = new_data_df.reset_index(drop=True)
    return new_data_df
