# A dictionary of movie critics and thier ratings of a small set of movies

critics={'Lisa Rose': {
        'Lady in the Water': 2.5,
        'Snakes on a Plane': 3.5,
        'Just My Luck': 3.0,
        'Superman Returns': 3.5,
        'You, Me and Dupree': 2.5,
        'The Night Listener': 3.0
        },
        'Gene Seymour': {
        'Lady in the Water':3.0 ,
        'Snakes on a Plane':3.5 ,
        'Just My Luck':1.5 ,
        'Superman Returns':5.0 ,
        'You, Me and Dupree': 3.5,
        'The Night Listener':3.0 
        },
        'Michael Phillips':{
        'Lady in the Water': 2.5,
        'Snakes on a Plane': 3.0,
        'Just My Luck': 3.5,
        'Superman Returns':3.5 ,
        'The Night Listener': 4.0
        },
        'Claudia Puig':{
        'Snakes on a Plane': 3.5,
        'Just My Luck': 2.0,
        'Superman Returns':4.0 ,
        'You, Me and Dupree': 2.5,
        'The Night Listener': 4.5
        },
        'Mick LaSalle':{
        'Lady in the Water': 3.0,
        'Snakes on a Plane': 4.0,
        'Just My Luck': 2.0,
        'Superman Returns':3.0 ,
        'You, Me and Dupree': 2.0,
        'The Night Listener': 3.0
        },
        'Jack Matthews':{
        'Lady in the Water': 3.0,
        'Snakes on a Plane': 4.0,
        'Superman Returns':5.0 ,
        'You, Me and Dupree':3.5 ,
        'The Night Listener':3.0 
        },
        'Toby':{
        'Snakes on a Plane': 4.5,
        'Superman Returns': 4.0,
        'You, Me and Dupree': 1.0,
        }
        }

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

            # flip item and person
            result[item][person]=prefs[person][item]
    return result
