Dataframe handling and conditional shift of cells

Question

I have data like below: df:

idx A B C D
0 0.0 0.0 0.1 apple
1 0.5 0.5 0.6 car
2 0.7 0.7 0.2 vegetables
3 0.8 0.9 0.4 fruits
4 0.9 1.0 0.8 metal
idx E 
0 0.000006