I have the following data:

I would like to know the average score for each item for each subject.
So I used the pivot table function in Python.

However, the average for each evaluator is calculated instead of the overall average, so this needs to be calculated again.

I used following code:

df_total_pv = pd.pivot_table(df_total, index='Subject', columns='Judge', values=['item1','item2','item3'], aggfunc='mean')

and the result was..

but I want to get a total mean,
like this:

How can I get this result?