我有以下df，我试图根据“ combined_sector”列中的值创建一个逗号分隔的列表。结果应如下所示：
IG信用：金融-雷曼兄弟部门：'46647PAY2'，'36164QMS4'，'36164QMS4'
高收益：工业-雷曼兄弟部门：'26112TAJ5'，'29273VAD2'
cusip sector_path_0 sector_path_1 sector_path_2 combined_sector
0 46647PAY2 FMBI UNIV Breakdown IG Credit Financials - Lehman Sector IG Credit: Financials - Lehman Sector
1 36164QMS4 FMBI UNIV Breakdown IG Credit Financials - Lehman Sector IG Credit: Financials - Lehman Sector
2 948741AH6 FMBI UNIV Breakdown IG Credit Financials - Lehman Sector IG Credit: Financials - Lehman Sector
3 26112TAJ5 FMBI UNIV Breakdown High Yield Industrials - Lehman Sector High Yield: Industrials - Lehman Sector
4 29273VAD2 FMBI UNIV Breakdown High Yield Industrials - Lehman Sector High Yield: Industrials - Lehman Sector
是否可以选择在哪些列上使用df['column'].values.tolist()？意思是，我可以选择从哪些列创建列表吗？