How can I change a specific row label in a Pandas dataframe?

Question

I have a dataframe such as:

      0     1    2    3    4    5
0  41.0  22.0  9.0  4.0  2.0  1.0
1   6.0   1.0  2.0  1.0  1.0  1.0
2   4.0   2.0  4.0  1.0  0.         


        

Answer 1

use index attribute:

 df.index = df.index[:-1].append(pd.Index(['A']))

Answer 2

You can get the last index using negative indexing similar to that in Python

last = df.index[-1]

Then

df = df.rename(index={last: 'a'})

Edit: If you are looking for a one-liner,

df.index = df.index[:-1].tolist() + ['a']