json输出键值对 python

数据：

{
    "2017-11-30": 990,
    "2017-12-01": 730,
    "2017-12-02": 620,
    "2017-12-03": 640,
    ...
}

import json
with open('fly.txt','r') as f:
    data = f.read()

j = json.loads(data)

for each in j:
    print each,j[each]

输出：