def src_from_cell_col(cell_name_col, verbose=False):
    """ Extract the source name from sample names. 
    Args:
        cell_name_col: the actual array of sample names
        verbose: print value_counts if True
    """
    src_names_arr = cell_name_col.map(lambda x: x.split('.')[0].lower())
    src_names_arr.name = 'source'
    if verbose:
        print(src_names_arr.value_counts())
    return src_names_arr