read a CSV file (ref_classes.csv) and return the 
    list of names

def read_file_1st_col_only(fname):
    """
    read a CSV file (ref_classes.csv) and return the 
    list of names
    """
    lst = []
    with open(fname, 'r') as f:
        _ = f.readline()   # read the header and ignore it
        for line in f:
            lst.append(line.split(',')[0])
    return lst