实现效果如下：
[
{"city": "上海",
"cityID": "shanghai",
"districts": [{"distrID": 1, "district": "浦东新区", "image": "/img/shanghai/pudong.jpg"},
{"distrID": 2, "district": "徐汇区", "image": "/img/shanghai/xuhui.jpg"},
{"distrID": 3, "district": "黄浦区", "image": "/img/shanghai/huangpu.jpg"}]
},
{"city": "北京",
"cityID": "beijing",
"districts": [{"distrID": 4, "district": "朝阳区", "image": "/img/beijing/chaoyang.jpg"},
{"distrID": 5, "district": "海淀区", "image": "/img/beijing/haidian.jpg"},
{"distrID": 6, "district": "昌平区", "image": "/img/beijing/changping.jpg"}]
}
]
def cityList(request):
cityDistinct = distrs.objects.values("city").distinct() //在distrs表中获取不同的城市
cities=[] //城市list
for i in cityDistinct: //对每个城市进行遍历
distrDistinct = distrs.objects.filter(district=i['city']) //从distrs表中获取该城市包含的区
districts = [] //区域list
for j in distrDistinct: //对每个区进行遍历，插入区域相关信息
districts.append({'distrID': j.distrID, 'district': j.district,
'image': j.image})
//对该城市的所有区遍历结束，将districts插入城市list中
cities.append({'city': i['city'], 'cityID': i['cityID'], 'districts': districts})
cities_json = json.dumps(cities, ensure_ascii=False)
return HttpResponse(cities_json)
