I was playing with pandas groupby function, and there is something I can't manage to achieve.

My data is like :

```
   data = ({
    'Color1':["Blue", "Red", "Green", "Blue", "Red", "Green", "Blue", "Red", "Green"],
    'Color2':["Purple", "Pink", "Yellow", "Purple", "Pink", "Yellow", "Brown", "White", "Grey"],
    'Value':[20, 20, 20, 25, 25, 25, 5, 55, 30]
})

df = pd.DataFrame(data)

```

I used the groupby to do some sorting (the idea behind is to extract some top N from larger datasets)

```
df2 = df.groupby(['Color1'], sort=True).sum()[['Value']].reset_index()
df2 = df2.sort_values(by=['Value'], ascending=False)
print(df2)

```

Color1 Value
2 Red 100
1 Green 75
0 Blue 50

But my biggest concern is how to groupby and sort adding Color2 while preserving the sort on Color 1 i.e. a result such as :

```
  Color1  Color2  Value
0    Red   White     55
1    Red    Pink     45
2  Green  Yellow     45
3  Green    Grey     30
4   Blue  Purple     45
5   Blue   Brown      5

```

Thanks a lot for your help