Apply Function on DataFrame Index

Question

What is the best way to apply a function over the index of a Pandas DataFrame? Currently I am using this verbose approach:

pd.DataFrame({\"Month\":          


        

Answer 1

Assuming that you want to make a column in you're current DataFrame by applying your function "foo" to the index. You could write...

df['Month'] = df.index.map(foo)

To generate the series alone you could instead do ...

pd.Series({x: foo(x) for x in foo.index})