如何在Python3中使用Kivy绘制一条简单的直线和一个矩形？

pip install kivy

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Line, Rectangle
from kivy.core.window import Window

class MyWidget(Widget):
    def draw(self):
        with self.canvas:
            # 绘制直线
            Line(points=[100, 100, 300, 100], width=2)
            
            # 绘制矩形
            Rectangle(pos=(200, 200), size=(100, 50))

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

if __name__ == '__main__':
    Window.clearcolor = (1, 1, 1, 1)  # 设置窗口背景颜色
    MyApp().run()