我想从数据框中创建一个新的数据框,如果索引已经存在,则创建新的列,但我不知道要创建多少个列:
pd.DataFrame([["John","guitar"],["Michael","football"],["Andrew","running"],["John","dancing"],["Andrew","cars"]])
and I want :
pd.DataFrame([["John","guitar","dancing"],["Michael","Football",None],["Andrew","running","cars"]])
在开始的时候,我不知道应该创建多少列。