How to rename the index of a Dask Dataframe

Question

How would I go about renaming the index on a dask dataframe? I tried it like so

df.index.name = 'foo'

but rechecking df.index.name shows it still being whatever it was previously.

Answer 1

This does not seem like an efficient way to do it, so I wouldn't be surprised if there is something more direct.

d.index.name starts off as 'foo';

def f(df, name):
    df.index.name = name
    return df

d.map_partitions(f, 'pow')

The output now has index name of 'pow'. If this is done with the threaded scheduler, I think you also change the index name of d in-place (in which case you don't really need the output of map_partitions).