如何在窗口初始化时调整QWidget在QSplitter中的垂直和水平比例？

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QSplitter, QWidget

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        splitter = QSplitter(self)
        self.setCentralWidget(splitter)

        left_widget = QWidget(splitter)
        right_widget = QWidget(splitter)

        splitter.addWidget(left_widget)
        splitter.addWidget(right_widget)

        splitter.setSizes([1, 2])  # 设置左右两个QWidget的初始大小比例为1:2

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MyWindow()
    window.show()
    sys.exit(app.exec_())