CSV conditional changes in rows and column

Question

I have data like below:

idx A B C D
0 0.0 0.0 apple
1 0.5 0.5 car
2 0.7 0.7 vegetables
3 0.8 0.9 fruits
4 0.9 1.0 metal
idx E 
0 Nr 0.000006
idx A B C D
0 1.0 1.1