如何在PyQt中使用pushButton清除绘图？

from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QLabel
from PyQt5.QtGui import QPainter, QColor, QPen
from PyQt5.QtCore import Qt

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        
        self.button = QPushButton('清除绘图', self)
        self.button.clicked.connect(self.clearDrawing)
        
        self.label = QLabel(self)
        self.label.setGeometry(10, 10, 200, 200)
        
        self.setGeometry(100, 100, 300, 300)
        self.setWindowTitle('绘图示例')
        
    def clearDrawing(self):
        self.label.clear()
        
    def paintEvent(self, event):
        painter = QPainter(self.label.pixmap())
        painter.setPen(QPen(Qt.red, 2, Qt.SolidLine))
        painter.drawRect(50, 50, 100, 100)
        painter.end()

if __name__ == '__main__':
    app = QApplication([])
    window = MyWindow()
    window.show()
    app.exec_()