Pythonic Way to reverse nested dictionaries

Question

I have a nested dictionary of people and item ratings, with people as the key. people may or may not share items. Example:

{
 \'Bob\' : {\'item1\':3, \'item2         


        

Answer 1

Pandas can provide another option. Assume data is the input dictionary.

import pandas as pd
output = {i:s.dropna().to_dict() for i, s in pd.DataFrame(data).T.iteritems()}