How to create an index that is both string and number for a dataframe?

I wish to create a column just like this:

İn Excel this can be done easily where the remaining rows can be auto-filled. How to achieve the same in python using pandas?

>Solution :

Use f-strings with zero fill values:

df['new'] = [f'abc_{n+1:02}' for n in range(len(df))]

If default index is possible add 1, convert to strings and add str.zfill:

df['new'] = 'abc_' + (df.index + 1).astype(str).str.zfill(2)