Kivy AttributeError:“super”对象没有属性“\uu getattr\uuuu”（尝试了以前的所有解决方案）

Question

这是Python中最烦人的错误之一，根据问题的不同，有很多解决方案

我的档案

Main.py

# imports
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen, ScreenManager


# Defining Screen, ScreenManager And App Classes:
class MainScreen(Screen):
    pass


class ShortCuts(Screen):
    pass


class WindowManager(ScreenManager):
    pass


# Kivy Lang Builder Packed As A Variable
BLD = Builder.load_file("KV_FILE.kv")


class OnlineClassMacros(App):

    # Initializing The App
    def __init__(self, **kwargs):
        super(OnlineClassMacros, self).__init__(**kwargs)

    # Defining The App By Referencing The Packed Kivy.Lang.Builder Variable Created At The Start Of The .py File
    def build(self):
        return BLD

    @staticmethod
    def Get():
        query = BLD.ids.SearchEngine.text

        print(query)


# ToDo: Monetize The >>Online Class Macros<< Application By Using KivMob


# MainLooping The Application Using  [if __name__ == "__main__":]
if __name__ == "__main__":
    OnlineClassMacros().run()

KV_FILE.kv

# Importing Our Function.py As A Python Module Into Kivy-Lang\

#######################################################
#:import redirect Function.redirect
#######################################################

# Pre-Styling Widgets
<Label>
    halign: 'center'
    valign: 'center'
    background_color: '0', '.4', '.3', '.4'
<Button>
    halign: 'center'
    valign: 'center'
    background_color: "0", ".1", ".1", ".8"

# Configuring The Screens And The Screen Manager
WindowManager:
    MainScreen:
    ShortCuts:

# Building All The Classes In Our "Main.py" File

<MainScreen>:
    name: "MainScreen"

    canvas.before:
        Rectangle:
            size: self.size
            pos: self.pos
            source: "Images/background 2.png"
    BoxLayout:
        orientation: "horizontal"
        BoxLayout:
            size_hint: .2,1
            orientation: "vertical"
            Button:
                text: "Google\nDocs"
                on_release: redirect("https://www.docs.google.com")
            Button:
                text: "Google\nSlides"
                on_release:
                    redirect("https://slides.google.com/u/0/h")
            Button:
                text: "Gmail"
                on_release:
                    redirect("https://www.gmail.com")
            Button:
                text: "Google\nClassroom"
                on_release:
                    redirect("https://classroom.google.com/u/0/")
        BoxLayout:
            size_hint: .6,1
            BoxLayout:
                orientation: "vertical"
                TextInput:
                    size_hint: 1, .2
                    multiline: True
                    hint_text: "Search here"
                    background_color: 1,1,1,.78
                    id: SearchEngine
                GridLayout:
                    cols: 3
                    Button:
                        text: "Google Scholar\nSearch"

                    Button:
                        text: "Wikipedia\nSearch"
                        on_release:
                            app.Get()
                    Button:
                        text: "Google\nSearch"
                    Button:
                        text: "RefSeek\nSearch"
                    Button:
                        text: "Microsoft Academic\nSearch"
                    Button:
                        text: "Hyper Search"
                        background_color: 1,0,0,.99
        BoxLayout:
            size_hint: .2,1
            orientation: "vertical"
            Button:
                text: "Google\nSpreadSheets"
                on_release:
                    redirect("https://classroom.google.com/u/0/h")
            Button:
                text: "MicroSoft\nTeams"
                on_release:
                    redirect("https://classroom.google.com/u/0/h")
            Button:
                text: "OutLook"
                on_release:
                    redirect("https://classroom.google.com/u/0/h")



<ShortCuts>:
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.pos
            source: 'Images/ Background 3.png'

错误：

C:\Users\mayan\AppData\Local\Programs\Python\Python39\python.exe "C:/Online Class Macros ;)/Main.py"
[INFO   ] [Logger      ] Record log in C:\Users\mayan\.kivy\logs\kivy_21-06-13_7.txt
[INFO   ] [deps        ] Successfully imported "kivy_deps.gstreamer" 0.3.2
[INFO   ] [deps        ] Successfully imported "kivy_deps.angle" 0.3.0
[INFO   ] [deps        ] Successfully imported "kivy_deps.glew" 0.3.0
[INFO   ] [deps        ] Successfully imported "kivy_deps.sdl2" 0.3.1
[INFO   ] [Kivy        ] v2.0.0
[INFO   ] [Kivy        ] Installed at "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\__init__.py"
[INFO   ] [Python      ] v3.9.4 (tags/v3.9.4:1f2e308, Apr  6 2021, 13:40:21) [MSC v.1928 64 bit (AMD64)]
[INFO   ] [Python      ] Interpreter at "C:\Users\mayan\AppData\Local\Programs\Python\Python39\python.exe"
[INFO   ] [Factory     ] 186 symbols loaded
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2, img_pil (img_ffpyplayer ignored)
[INFO   ] [Window      ] Provider: sdl2
[INFO   ] [GL          ] Using the "OpenGL" graphics system
[INFO   ] [GL          ] GLEW initialization succeeded
[INFO   ] [GL          ] Backend used <glew>
[INFO   ] [GL          ] OpenGL version <b'4.0.0 - Build 10.18.10.5059'>
[INFO   ] [GL          ] OpenGL vendor <b'Intel'>
[INFO   ] [GL          ] OpenGL renderer <b'Intel(R) HD Graphics'>
[INFO   ] [GL          ] OpenGL parsed version: 4, 0
[INFO   ] [GL          ] Shading version <b'4.00 - Build 10.18.10.5059'>
[INFO   ] [GL          ] Texture max size <16384>
[INFO   ] [GL          ] Texture max units <16>
[INFO   ] [Window      ] auto add sdl2 input provider
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[INFO   ] [GL          ] NPOT texture support is available
[INFO   ] [GL          ] Unpack subimage support is available
[INFO   ] [Text        ] Provider: sdl2
[INFO   ] [Base        ] Start application main loop
[INFO   ] [Base        ] Leaving application in progress...
 Traceback (most recent call last):
   File "kivy\properties.pyx", line 861, in kivy.properties.ObservableDict.__getattr__
 KeyError: 'SearchEngine'
 
 During handling of the above exception, another exception occurred:
 
 Traceback (most recent call last):
   File "C:\Online Class Macros ;)\Main.py", line 46, in <module>
     OnlineClassMacros().run()
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\app.py", line 950, in run
     runTouchApp()
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\base.py", line 582, in runTouchApp
     EventLoop.mainloop()
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\base.py", line 347, in mainloop
     self.idle()
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\base.py", line 391, in idle
     self.dispatch_input()
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\base.py", line 342, in dispatch_input
     post_dispatch_input(*pop(0))
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\base.py", line 308, in post_dispatch_input
     wid.dispatch('on_touch_up', me)
   File "kivy\_event.pyx", line 709, in kivy._event.EventDispatcher.dispatch
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\uix\behaviors\button.py", line 179, in on_touch_up
     self.dispatch('on_release')
   File "kivy\_event.pyx", line 705, in kivy._event.EventDispatcher.dispatch
   File "kivy\_event.pyx", line 1248, in kivy._event.EventObservers.dispatch
   File "kivy\_event.pyx", line 1132, in kivy._event.EventObservers._dispatch
   File "C:\Users\mayan\AppData\Local\Programs\Python\Python39\lib\site-packages\kivy\lang\builder.py", line 57, in custom_callback
     exec(__kvlang__.co_value, idmap)
   File "C:\Online Class Macros ;)\KV_FILE.kv", line 70, in <module>
     app.Get()
   File "C:\Online Class Macros ;)\Main.py", line 36, in Get
     query = BLD.ids.SearchEngine.text
   File "kivy\properties.pyx", line 864, in kivy.properties.ObservableDict.__getattr__
 AttributeError: 'super' object has no attribute '__getattr__'

Process finished with exit code 1

这个错误以前发生在我身上，我解决了它，但正如我所说，答案取决于问题。 如果没有人删除我的问题，说这是重复的，我将不胜感激

Answer 1

神秘的错误消息帮助不大，但堆栈跟踪显示错误发生在以下行：

query = BLD.ids.SearchEngine.text

此行失败的原因是您试图访问id（SearchEngine）对象中不存在的BLD。BLD对象是kv的根，它是WindowManager，但是SearchEngine{}是在<MainScreen>:规则中定义的。因此，修复方法是通过正确的对象访问该id：

def Get():
    app = App.get_running_app()  # get a refrence to the running App
    main_screen = app.root.get_screen('MainScreen')  # get a reference to the MainScreen
    query = main_screen.ids.SearchEngine.text  # now use the id

    print(query)

注意documentation表示：

When the kv file is processed, weakrefs to all the widgets tagged with ids are added to the root widget’s ids dictionary.

那份文件是不正确的。ids实际上是添加到包含id的规则的基本对象，而不是添加到kv文件的根小部件