def _format_list_str(values, sep=',', item_format=str):
    if sep is None:
        joiner = ' '
    else:
        joiner = sep + ' '
    s = joiner.join(item_format(x) for x in values)
    return s
Convert a list to a string.
dataset/ETHPy150Open enthought/traitsui/traitsui/editors/csv_list_editor.py/_format_list_str