互换键值位置

change_k_v.py

#!/usr/bin/env python3  
# -*- coding: utf-8 -*-  
"""  
 @desc:  互换键值位置
 @author: Bingo Cai
"""

prefs = {'Lady in the water':{'Lisa Rose':2.5, 'Gene Seymour':3.0},
                'Lady in the moon':{'Lisa Rose':3.5, 'Gene Seymour':2.0},
                'spring festival':{'Lisa Rose':1.5, 'Gene Seymour':1.0},
                'happy everyday':{'Lisa Rose':3.5, 'Gene Seymour':4.0},
               }

def transformPrefs(prefs):
    result = {}
    for person in prefs:
        for item in prefs[person]:
            result.setdefault(item, {})
            result[item][person] = prefs[person][item]
    print(result)

transformPrefs(prefs)