Find the row which has the maximum difference between two columns

Instead of .where, you can use .idxmax:

(df['Gold'] - df['Gold.1']).idxmax()
Out: 6

This will return the index where the difference is maximum.

If you want to find the row with the maximum absolute difference, then you can call .abs() first.

(df['Gold'] - df['Gold.1']).abs().idxmax()
Out: 4