Python - Kivymd 错误：属性错误：“超级”对象没有属性“__getattr__”

Question

我为 Kivymd 程序编写了这段代码，用于求解数学方程。我没有添加求解对象，因为它们太长了，但是，我会尽力使问题尽可能清晰

这是代码：

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivymd.uix.screen import MDScreen
from kivy.properties import DictProperty
from kivymd.uix.screenmanager import MDScreenManager

__version__ = "1.0.0"

kv = """WindowManager:
    Home:
    Heugebra:

<Home>:
    name: "Home"


    FloatLayout:
        orientation: "vertical"

        MDCard:
            size: 500,400

            FloatLayout:
                size: 500,400

                MDTextField:
                    id: Equ
                    hint_text: "Insert the Equation"
                    size_hint: None,None
                    width: 200
                    pos_hint: {"x": 0.3,"y": 0.3}
                    on_text_validate: root.get_data()
                MDLabel:
                    id: Eq_anser
                    text: "test"
                    pos_hint: {"x": 0.4,"y": 0.3}
                MDRoundFlatButton:
                    text: "Cal"
                    pos_hint: {"x": 0.8,"y": 0.3}
                    on_press: app.get_data()
                MDRoundFlatButton:
                    text: "Expand"
                    pos_hint: {"X": 0.4, "y": 0.3}
                    on_press: app.expand()
                MDRoundFlatButton:
                    text: "Draw"
                    pos_hint: {"x": 0.4,"y": 0.25}
                    on_release:
                        app.root.current = "Heugebra"
                        root.manager.transition.direction = "left"
                MDFloatingActionButtonSpeedDial:
                    data: app.data
                    root_button_anim: True
<Heugebra>:
    name: "Heugebra"

    MDRoundFlatButton:
        text: "Back to Home"
        pos_hint: {"x": 0.3, "Y": 0.5}
        on_release:
            app.root.current = "Home"
            root.manager.transition.direction = "right"

"""

class WindowManager(MDScreenManager):
    pass

class Home(MDScreen):
    pass

class Heugebra(MDScreen):
    pass

class MAIN(MDApp):
    data = DictProperty()

    def on_start(self):
        Window.set_title('Every Solver')

    def build(self):
        self.theme_cls.theme_style = "Dark"
        self.theme_cls.primary_palette = "Indigo"
        self.data = {
                "Integrate": ["math-integral",
                        "on_press", lambda x: self.calculas('int')],
                "Diff": ["math-diff.png",
                        "on_press", lambda x: self.calculas('diff')],
        }
        return Builder.load_string(kv)

    def calculas(self, calc: str):
        print(calc)

    def get_data(self):
        x = self.root.ids.Equ.text
        self.root.ids.Eq_anser.text = "None"

    def expand(self):
        x = self.root.ids.Equ.text
        self.root.ids.Eq_anser.text = "None"

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

问题是当我尝试单击“Sol”或“Expand”按钮时，会出现此错误： AttributeError：“超级”对象没有属性“getattr”。您的意思是：“setattr”吗？

Answer 1

问题是

self.root

（

ScreenManager

）引用的小部件没有Equ或Eq_anser ids。

请注意，ids 可在定义它们的规则内访问，包含这些 ids 的字典是

Home

实例

ids

字典，这是定义它们的规则：

<Home>:
    name: "Home"
    FloatLayout:
        MDCard:
            FloatLayout:
                MDTextField:
                    id: Equ
                MDLabel:
                    id: Eq_anser

因此，要访问它们，您需要引用

Home

实例，例如：

def get_data(self):
    x = self.root.get_screen("Home").ids.Equ.text.
    self.root.get_screen("Home").ids.Eq_anser.text = "None".

def expand(self):
    x = self.root.get_screen("Home").ids.Equ.text
    self.root.get_screen("Home").ids.Eq_anser.text = "None"