Pandas groupby in combination with sklearn preprocessing

Question

I want to group my DataFrame by specific column and then apply a sklearn preprocessing MinMaxScaler and store the scaler object.

My at the moment starting point:

Answer 1

you can do it in one direction:

In [62]: from sklearn.preprocessing import minmax_scale

In [63]: df
Out[63]:
  ID   VL  SC
0  A    0   0
1  A   10   1
2  A   10   1
3  B  100   0
4  B  100   0
5  B  200   1

In [64]: df['SC'] = df.groupby('ID').VL.transform(lambda x: minmax_scale(x.astype(float)))

In [65]: df
Out[65]:
  ID   VL  SC
0  A    0   0
1  A   10   1
2  A   10   1
3  B  100   0
4  B  100   0
5  B  200   1

but you will not be anle to use inverse_transform as each call of MinMaxScaler (for each group or each ID) will overwrite the information about your orginal features...