python kivy AttributeError:'super'对象没有属性&

问题描述

对于一个项目，我正在尝试制作一个简单的 GUI，它显示一些基本信息(如时间、日期、公共交通信息、一些新闻等).为此，我想要一个显示所有这些内容概览的主页以及每个主题的特殊页面，并提供详细视图.Python 与 Kivy 相结合似乎是最好/最简单的解决方案，看起来不错，而且工作起来也很简单.但是，我在显示时间时遇到了问题.当我尝试更新标签上显示时间的文本时，我得到一个 AttributeError: 'super' object has no attribute '__getattr__'，这并没有给我提供太多关于在哪里寻找的信息一个解法.谁能指出哪里出了问题?

for a project I'm trying to make a simple GUI which displays some basic information (like time, date, public transport info, some news etc.) To do this I want a Homepage that displays an overview of all these things and a special page for every subject with a detailed view. Python combined with Kivy seemed like the best/easiest solution that looks good and works quite easy. I am however getting a problem with displaying the time. When I try to update the text on the label that displays the time I get an AttributeError: 'super' object has no attribute '__getattr__', which does not give me much information as to where to look for a solution. Can anyone point out what's wrong?

main.py:

import feedparser
import time
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.anchorlayout import AnchorLayout
from kivy.properties import NumericProperty, ReferenceListProperty, ObjectProperty, StringProperty
from kivy.uix.label import Label
from kivy.uix.widget import Widget
from kivy.clock import Clock

# Declare widgets
class DateTime(Widget):
    curtime = StringProperty('')

    def update(self, dt):
        self.curtime = time.strftime("%H:%M:%S")
        print self.curtime
        self.ids["kv_timelabel"].text = str(self.curtime)

# Declare all screens
class HomeScreen(Screen):
    obj_datetime = DateTime()
    Clock.schedule_interval(obj_datetime.update, 1.0 / 10.0)

class NewsScreen(Screen):
    pass

class PublicTransportScreen(Screen):
    pass

class TrafficScreen(Screen):
    pass

class ScreenManagement(ScreenManager):
    pass

class MirrorApp(App):
    def build(self):
        # Create the screen manager
        render = ScreenManagement()
        render.add_widget(HomeScreen(name='home'))
        render.add_widget(TrafficScreen(name='traffic'))
        render.add_widget(PublicTransportScreen(name='public_transport'))
        render.add_widget(NewsScreen(name='news'))
        return render

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

mirror.kv:

#:kivy 1.9.0

<HomeScreen>:
    name: 'home'
    obj_datetime: kv_datetime

    Button:
        on_release: app.root.current = 'news'
        text: 'News'
        size_hint: 0.5,0.15
        font_size: 50
        pos_hint: {"left":1, "top":0.15}

    Button:
        on_release: app.root.current = 'public_transport'
        text: 'Public Transport'
        size_hint: 0.5,0.15
        font_size: 50
        pos_hint: {"left":1, "top":0.3}

    Button:
        on_release: app.root.current = 'traffic'
        text: 'Traffic'
        size_hint: 0.5,0.15
        font_size: 50
        pos_hint: {"left":1, "top":0.45}

    DateTime:
        id: kv_datetime
        center: self.parent.center

<NewsScreen>:
    name: 'news'

    Button:
        on_release: app.root.current = 'home'
        text: 'back to the home screen'
        font_size: 50

<PublicTransportScreen>:
    name: 'public_transport'

    Button:
        on_release: app.root.current = 'home'
        text: 'back to the home screen'
        font_size: 50

<TrafficScreen>:
    name: 'traffic'

    Button:
        on_release: app.root.current = 'home'
        text: 'back to the home screen'
        font_size: 50

<DateTime>:
    Label:
        id: kv_timelabel
        text:
        font_size: 70  
        center_x: self.parent.center_x
        center_y: self.parent.center_y

我在运行 main.py 时遇到的错误是(我认为这个错误的最后两行左右就足够了，但你永远不够彻底):

The error I get when running main.py is (I think the last two lines or so of this error are enough, but you can never be thorough enough):

[INFO   ] [Logger      ] Record log in /home/matthias/.kivy/logs/kivy_16-04-17_97.txt
[INFO   ] [Kivy        ] v1.9.0
[INFO   ] [Python      ] v2.7.10 (default, Oct 14 2015, 16:09:02) 
[GCC 5.2.1 20151010]
[INFO   ] [Factory     ] 173 symbols loaded
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_gif, img_sdl2, img_pil (img_ffpyplayer ignored)
[INFO   ] [Text        ] Provider: sdl2
[INFO   ] [OSC         ] using <multiprocessing> for socket
[INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[INFO   ] [GL          ] OpenGL version <3.0 Mesa 11.0.2>
[INFO   ] [GL          ] OpenGL vendor <Intel Open Source Technology Center>
[INFO   ] [GL          ] OpenGL renderer <Mesa DRI Intel(R) Ivybridge Mobile >
[INFO   ] [GL          ] OpenGL parsed version: 3, 0
[INFO   ] [GL          ] Shading version <1.30>
[INFO   ] [GL          ] Texture max size <8192>
[INFO   ] [GL          ] Texture max units <16>
[INFO   ] [Window      ] auto add sdl2 input provider
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[INFO   ] [ProbeSysfs  ] device match: /dev/input/event5
[INFO   ] [MTD         ] Read event from </dev/input/event5>
[INFO   ] [Base        ] Start application main loop
[INFO   ] [GL          ] NPOT texture support is available
19:39:33
[INFO   ] [Base        ] Leaving application in progress...
 Traceback (most recent call last):
   File "main.py", line 49, in <module>
     MirrorApp().run()
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 824, in run
 Exception in thread Thread-1:
     runTouchApp()
 Traceback (most recent call last):
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 487, in runTouchApp
     EventLoop.window.mainloop()
   File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 525, in mainloop
     self.run()
     self._mainloop()
   File "/usr/lib/python2.7/threading.py", line 763, in run
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 290, in _mainloop
     self.__target(*self.__args, **self.__kwargs)
     EventLoop.idle()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 327, in idle
   File "/usr/lib/python2.7/dist-packages/kivy/input/providers/mtdev.py", line 197, in _thread_run
     Clock.tick()
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 483, in tick
     self._process_events()
     _device = Device(_fn)
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 615, in _process_events
   File "/usr/lib/python2.7/dist-packages/kivy/lib/mtdev.py", line 131, in __init__
     self._fd = os.open(filename, os.O_NONBLOCK | os.O_RDONLY)
 OSError: [Errno 13] Permission denied: '/dev/input/event5'

     event.tick(self._last_tick, remove)
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 374, in tick
     ret = callback(self._dt)
   File "main.py", line 19, in update
     self.ids["kv_timelabel"].text = str(self.curtime)
 KeyError: 'kv_timelabel'

当我将 self.ids["kv_timelabel"].text = str(self.curtime) 替换为 self.ids.kv_timelabel.text = str(self.curtime)代码> 我明白了:

When I replace self.ids["kv_timelabel"].text = str(self.curtime) with self.ids.kv_timelabel.text = str(self.curtime) I get:

[INFO   ] [Logger      ] Record log in 
/home/matthias/.kivy/logs/kivy_16-04-17_98.txt
[INFO   ] [Kivy        ] v1.9.0
[INFO   ] [Python      ] v2.7.10 (default, Oct 14 2015, 16:09:02) 
[GCC 5.2.1 20151010]
[INFO   ] [Factory     ] 173 symbols loaded
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_gif, img_sdl2, img_pil (img_ffpyplayer ignored)
[INFO   ] [Text        ] Provider: sdl2
[INFO   ] [OSC         ] using <multiprocessing> for socket
[INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[INFO   ] [GL          ] OpenGL version <3.0 Mesa 11.0.2>
[INFO   ] [GL          ] OpenGL vendor <Intel Open Source Technology Center>
[INFO   ] [GL          ] OpenGL renderer <Mesa DRI Intel(R) Ivybridge Mobile >
[INFO   ] [GL          ] OpenGL parsed version: 3, 0
[INFO   ] [GL          ] Shading version <1.30>
[INFO   ] [GL          ] Texture max size <8192>
[INFO   ] [GL          ] Texture max units <16>
[INFO   ] [Window      ] auto add sdl2 input provider
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[INFO   ] [ProbeSysfs  ] device match: /dev/input/event5
[INFO   ] [MTD         ] Read event from </dev/input/event5>
[INFO   ] [Base        ] Start application main loop
[INFO   ] [GL          ] NPOT texture support is available
19:42:01
[INFO   ] [Base        ] Leaving application in progress...
 Traceback (most recent call last):
   File "main.py", line 49, in <module>
 Exception in thread Thread-1:
 Traceback (most recent call last):
   File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
     self.run()
   File "/usr/lib/python2.7/threading.py", line 763, in run
     MirrorApp().run()
     self.__target(*self.__args, **self.__kwargs)
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 824, in run
   File "/usr/lib/python2.7/dist-packages/kivy/input/providers/mtdev.py", line 197, in _thread_run
     runTouchApp()
     _device = Device(_fn)
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 487, in runTouchApp
   File "/usr/lib/python2.7/dist-packages/kivy/lib/mtdev.py", line 131, in __init__
     EventLoop.window.mainloop()
     self._fd = os.open(filename, os.O_NONBLOCK | os.O_RDONLY)
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 525, in mainloop
 OSError: [Errno 13] Permission denied: '/dev/input/event5'
     self._mainloop()

   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_sdl2.py", line 290, in _mainloop
     EventLoop.idle()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 327, in idle
     Clock.tick()
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 483, in tick
     self._process_events()
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 615, in _process_events
     event.tick(self._last_tick, remove)
   File "/usr/lib/python2.7/dist-packages/kivy/clock.py", line 374, in tick
     ret = callback(self._dt)
   File "main.py", line 19, in update
     self.ids.kv_timelabel.text = str(self.curtime)
   File "kivy/properties.pyx", line 720, in kivy.properties.ObservableDict.__getattr__ (kivy/properties.c:10938)
 AttributeError: 'super' object has no attribute '__getattr__'

请注意，当我删除错误中提到的行时，代码可以正常工作.

Note that the code works just fine when I delete the line it mentions in the error.

推荐答案

将kv文件的加载移到widget之前.所以调用 Builder.loadfile("mirror.kv") 然后声明你的类 DateTime 和 HomeScreen (因为它使用 DateTime).您得到的关键错误可能是因为此小部件还没有具有该 id 的孩子.