TypeError:add_widget（）缺少1个必需的位置参数：“widget”

Question

我和Tim在遵循Tech提供的Kivy教程时遇到了一个错误（TypeError:add_widget（）缺少1个必需的位置参数：“widget”），我不知道如何解决这个错误，下面是源代码：

import kivy
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button

class MyGrid(GridLayout):
    def __init__(self, **kwargs):
        super(MyGrid, self).__init__(**kwargs)
        self.cols = 1

        self.inside = GridLayout
        self.inside.cols = 2

        self.inside.add_widget(Label(text='Name: '))        *<---- ERROR HERE*
        self.name = TextInput(multiline=False)
        self.inside.add_widget(self.name)

        self.inside.add_widget(Label(text='Last name: '))
        self.lastName = TextInput(multiline=False)
        self.inside.add_widget(self.lastName)

        self.inside.add_widget(Label(text='Email: '))
        self.email = TextInput(multiline=False)
        self.inside.add_widget(self.email)

        self.add_widget(self.inside)

        self.submit = Button(text='Click Me!', font_size=20)
        self.add_widget(self.submit)


class MyApp(App):
    def build(self):
        return MyGrid()


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

Answer 1

将self.inside = GridLayout更改为self.inside = GridLayout()