解析JSON python时字符串索引必须是整数

Question

我是python新手，在分析JSON文件时遇到了这个错误：string indices must be integers。

JSON文件：

{"NFLTeams": [
  {"code":"ARI","fullName":"Arizona Cardinals","shortName":"Arizona"},
  {"code":"ATL","fullName":"Atlanta Falcons","shortName":"Atlanta"},
  {"code":"WAS","fullName":"Washington Redskins","shortName":"Washington"}
]}

我的代码：

import urllib.request as ur
import urllib.parse
import json

url = 'http://www.fantasyfootballnerd.com/service/nfl-teams/json/test/'
user_agent = 'Mozilla/5.0 (Windows NT 6.1; Win64; x64)'
values = {'name' : 'Michael Foord',
          'location' : 'Northampton',
          'language' : 'Python' }
headers = { 'User-Agent' : user_agent }

data = urllib.parse.urlencode(values)
data = data.encode('ascii')
req = urllib.request.Request(url, data, headers)
response = urllib.request.urlopen(req)
the_page = response.read().decode('utf-8')

print (the_page)
team_data = json.loads(the_page)

print (type(team_data))  // team_data is type dict

for item in team_data:
    print (item['NFLTeams'][0]["code"])
    print (item['NFLTeams'][0]['fullName'])
    print (item['NFLTeams'][0]['shortName'])

我试图打印以下内容：

print (item['NFLTeams']["code"]) 

而这个：

for item in team_data['NFLTeams'].values():
    print (item["code"])
    print (item['fullName'])
    print (item['shortName'])

这就给了我一个错误：

for item in team_data['NFLTeams'].values():
AttributeError: 'list' object has no attribute 'values'

有谁能帮我弄清楚发生了什么事吗？谢谢您。