change pandas MultiIndex level by '+1'

Question

How to rename MultiIndex level = 0 as mentioned in this_df like 'ti'->'ti+1'?

this_df contains normalized weights using ti data for computing weighted sums in ti+1.

this_df = pd.read_csv('http://www.boomboxbooking.de/stackq/data.csv', index_col =[0,1], sep=';')

new_index_level_0 = ['t1','t2','t3']

Answer 1

Use set_levels on the Index object to assign new values:

In[72]:
this_df.index = this_df.index.set_levels(['t1','t2','t3'], 0)
this_df

Out[72]: 
               earnings  costs
   Unnamed: 1                 
t1 S1              0.50   0.50
   S2              0.50   0.50
t2 S1              0.20   0.09
   S2              0.80   0.91
t3 S1              0.43   0.20
   S2              0.57   0.80