python和json，錯誤-TypeError：字符串索引必須為整數

Question

我學習了制作Android應用程序的知識。 所以我讀了《在Kivy中創建應用程序》一書。 遵循說明時遇到錯誤。

我的python代碼如下。

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty
from kivy.network.urlrequest import UrlRequest
import json
import urllib
import urllib.request
import codecs

class AddLocationForm(BoxLayout):

    search_input = ObjectProperty()
    search_results = ObjectProperty()


    def search_location(self):
        search_template = 'http://api.openweathermap.org/data/2.5/' + 'weather?q={}&&APPID=d9733213314ecfdbd08f9753d38444bf'
        search_url = search_template.format(self.search_input.text)
        u = urllib.request.urlopen(search_url)
        data = u.read().decode('utf-8')
        print(type(data))
        # request = UrlRequest(search_url, self.found_location)
        self.found_location(data)

    def found_location(self, data):
        # reader = codecs.getreader("utf-8")
        data2 = json.loads(data)
        # data2 = reader(data).json()
        print(data2)
        for i in data2:
            cities = ['{} ({})'.format(i['name'],i['sys']['country'])]
            self.search_results.item_strings = cities

class WeatherApp(App):
    pass

if __name__ == '__main__':
    WeatherApp().run()

我的錯誤是

 Traceback (most recent call last):
   File "E:\Weather\main.py", line 52, in <module>
     WeatherApp().run()
   File "C:\Python34\lib\site-packages\kivy\app.py", line 828, in run
 runTouchApp()
   File "C:\Python34\lib\site-packages\kivy\base.py", line 487, in runTouchApp
     EventLoop.window.mainloop()
   File "C:\Python34\lib\site-packages\kivy\core\window\window_sdl2.py", line 619, in mainloop
     self._mainloop()
   File "C:\Python34\lib\site-packages\kivy\core\window\window_sdl2.py", line 362, in _mainloop
     EventLoop.idle()
   File "C:\Python34\lib\site-packages\kivy\base.py", line 330, in idle
     self.dispatch_input()
   File "C:\Python34\lib\site-packages\kivy\base.py", line 315, in dispatch_input
     post_dispatch_input(*pop(0))
   File "C:\Python34\lib\site-packages\kivy\base.py", line 221, in post_dispatch_input
     listener.dispatch('on_motion', etype, me)
   File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:7699)
   File "C:\Python34\lib\site-packages\kivy\core\window\__init__.py", line 1030, in on_motion
     self.dispatch('on_touch_down', me)
  File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:7699)
   File "C:\Python34\lib\site-packages\kivy\core\window\__init__.py", line  1046, in on_touch_down
     if w.dispatch('on_touch_down', touch):
   File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:7699)
   File "C:\Python34\lib\site-packages\kivy\uix\widget.py", line 432, in on_touch_down
     if child.dispatch('on_touch_down', touch):
   File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:7699)
   File "C:\Python34\lib\site-packages\kivy\uix\widget.py", line 432, in on_touch_down
     if child.dispatch('on_touch_down', touch):
   File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch  (kivy\_event.c:7699)
   File "C:\Python34\lib\site-packages\kivy\uix\behaviors\button.py", line  110, in on_touch_down
     self.dispatch('on_press')
   File "kivy\_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch   (kivy\_event.c:7654)
   File "kivy\_event.pyx", line 1224, in kivy._event.EventObservers.dispatch   (kivy\_event.c:13497)
   File "kivy\_event.pyx", line 1108, in    kivy._event.EventObservers._dispatch (kivy\_event.c:12329)
   File "C:\Python34\lib\site-packages\kivy\lang.py", line 1557, in     custom_callback
     exec(__kvlang__.co_value, idmap)
   File "E:\Weather\weather.kv", line 89, in <module>
 on_press: root.search_location()
   File "E:\Weather\main.py", line 35, in search_location
 self.found_location(data)
   File "E:\Weather\main.py", line 43, in found_location
     cities = ['{} ({})'.format(i['name'],i['sys']['country'])]
 TypeError: string indices must be integers

和json內容是

{
"coord":{"lon":-123.12,"lat":49.25},
"weather":[{"id":800,"main":"Clear","description":"clearsky","icon":"02n"}],
"base":"stations",
"main":{"temp":265.29,"pressure":1022,"humidity":73,"temp_min":263.15,"temp_max":267.15    },
"visibility":48279,
"wind":{"speed":2.6,"deg":80},"clouds":{"all":5},"dt":1484230500,
"sys":{"type":1,"id":3359,"message":0.0149,"country":"CA","sunrise":1484237006,"sunset":1484267964},
"id":6173331,"name":"Vancouver","cod":200}

我該如何解決？

Answer 1

您僅獲得1條記錄作為dict，因此不需要循環。

def found_location(self, data):
    # reader = codecs.getreader("utf-8")
    data2 = json.loads(data)
    # data2 = reader(data).json()
    print(data2)
    cities = ['{} ({})'.format(data2['name'],data2['sys']['country'])]
    self.search_results.item_strings = cities

Answer 2

您使用的是字符串的索引，而不是您認為的字典

for i in data2:
    cities = ['{} ({})'.format(i['name'],i['sys']['country'])]
    self.search_results.item_strings = cities

正如tdelaney在評論中提到的那樣，您要遍歷dict，然后嘗試在其中放入字符串的索引。

也請參閱此帖子 。