数据帧
df = pd.DataFrame({'A': [['gener'], ['gener'], ['system'], ['system'], ['gutter'], ['gutter'], ['gutter'], ['gutter'], ['gutter'], ['gutter'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum'], ['aluminum', 'toledo']], 'B': [['gutter'], ['gutter'], ['gutter', 'system'], ['gutter', 'guard', 'system'], ['ohio', 'gutter'], ['gutter', 'toledo'], ['toledo', 'gutter'], ['gutter'], ['gutter'], ['gutter'], ['how', 'to', 'instal', 'aluminum', 'gutter'], ['aluminum', 'gutter'], ['aluminum', 'gutter', 'color'], ['aluminum', 'gutter'], ['aluminum', 'gutter', 'adrian', 'ohio'], ['aluminum', 'gutter', 'bowl', 'green', 'ohio'], ['aluminum', 'gutter', 'maume', 'ohio'], ['aluminum', 'gutter', 'perrysburg', 'ohio'], ['aluminum', 'gutter', 'tecumseh', 'ohio'], ['aluminum', 'gutter', 'toledo', 'ohio']]}, columns=['A', …