如何从QSplitter中删除QWidgets

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QPushButton, QSplitter

class Example(QWidget):
    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        vbox = QVBoxLayout(self)

        splitter = QSplitter(self)
        splitter.setOrientation(Qt.Vertical)

        widget1 = QWidget()
        widget2 = QWidget()
        widget3 = QWidget()

        splitter.addWidget(widget1)
        splitter.addWidget(widget2)
        splitter.addWidget(widget3)

        btn = QPushButton('Remove Widget 2', self)
        btn.clicked.connect(lambda: self.removeWidget(widget2))

        vbox.addWidget(splitter)
        vbox.addWidget(btn)

        self.setLayout(vbox)

    def removeWidget(self, widget):
        splitter = self.findChild(QSplitter)
        index = splitter.indexOf(widget)

        if index != -1:
            splitter.removeWidget(widget)
            widget.deleteLater()

if __name__ == '__main__':
    app = QApplication([])
    ex = Example()
    ex.show()
    app.exec_()