Python django restframework显示格式

我有一个端点，它给出如下响应：

 {
    "theatershowtime"   : [
        {
            "movietime" : "2014-11-23T02:40:00Z", 
            "mvtype"    : "3D"
        }, 
        {
            "movietime" : "2014-11-23T05:40:00Z", 
            "mvtype"    : "3D"
        }, 
        {
            "movietime" : "2014-11-23T03:40:00Z", 
            "mvtype"    : "IMAX"
        }, 
    ]   

}

这是my serializes.py：

class TheaterSerializer(serializers.ModelSerializer):
    theatershowtime = MovieShowtimeSerializer(many=True, read_only=True, source='theater')

    class Meta:
        model = MovieTheater
        fields = ('theatershowtime',  )


class MovieShowtimeSerializer(serializers.ModelSerializer):
    class Meta:
        model = MovieShowtime
        fields = ( 'movietime', 'mvtype',  )

我学习了一种方法，如何像这样表现：

 "Times": [
       "2014-11-23T02:40:00Z",
        "2014-11-23T05:40:00Z",
       "2014-11-23T03:40:00Z",
]

使用此serializes.py是非常有用的：

class TheaterSerializer(serializers.ModelSerializer):
    Times = serializers.SerializerMethodField('get_movietimes') 
    def get_movietimes(self, obj):
        movietimes = []
        for i in obj.theater.all():
            movietimes.append(i.movietime)
        return movietimes


    class Meta:
        model = MovieTheater
        fields = ('Times',  )

但我希望得到这样的回应：

theatershowtime: {
            Times: {
                3D: [
                    "2014-11-23T02:40:00Z",
                    "2014-11-23T05:40:00Z",
                ],
                IMAX: [ 
                    "2014-11-23T03:40:00Z",
                ]
            }
},

---

请帮帮我！非常感谢

尝试使用此代码段：

...
def get_movietimes(self, obj):
    movietimes = {}
    for i in obj.theater.all():
        if i.mvtype not in movietimes:
            movietimes[i.mvtype] = []
        movietimes[i.mvtype].append(i.movietime)
    return movietimes
...