python - Pandas - Dataframe.set_index - how to keep the old index column

Question

I have this Dataframe:

import pandas as pd
df = pd.DataFrame({\'Hugo\' : {\'age\' : 21, \'weight\' : 75},
                   \'Bertram\': {\'age\' :         


        

Answer 1

Use reset_index first and then set_index:

df = df.reset_index().set_index('age')
print (df)
        name  weight
age                 
45   Bertram      65
75    Donald      85
21      Hugo      75