def build_index(df, index_list):
    """
    Build a new Index for the DataFrame
    :param df: dfOld or New
    :return: a new dataframe
    """
    df1 = df.copy()
    df1['General ID'] = ''
    for x in index_list:
        df1['General ID'] = df1['General ID'].map(str) + df1[x].map(str) + '-'
    df1['General ID'] = df1['General ID'].str.rstrip('-')
    return df1, 'General ID'
