How to speed up Pandas multilevel dataframe shift by group?

Question

I am trying to shift the Pandas dataframe column data by group of first index. Here is the demo code:

 In [8]: df = mul_df(5,4,3)

In [9]: df
Out[9]:
                    


        

Answer 1

How about shift the total DataFrame object and then set the first row of every group to NaN?

dfs = df.shift(1)
dfs.iloc[df.groupby(level=0).size().cumsum()[:-1]] = np.nan