I have a dataframe with a column multiindex and various data columns:

                 id value1 value2  valuen
name  date
foo   01-2000  No01    324   6575     ...
bar   02-2000  No02    964   0982     ...

Now I need to turn id into a number (df['id'] = df[id].str[1:]; df['id'] = df['id'].astype(int)) and add this as a third column to the multiindex.

Of course there’s various ways to do that, but I’m wondering if there is one of the many, inbuilt pandas shortcuts for it, i.e. something like pd.make_index_col(df['id']) or df.add_to_index('id') to get a df with, in this case, 3 index columns:

                  value1 value2  valuen
name  date     id
foo   01-2000   1    324   6575     ...
bar   02-2000   2    964   0982     ...