如何在PyQt5中创建动态网格QScrollarea？

from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QScrollArea, QGridLayout, QLabel, QPushButton

class MainWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.layout = QVBoxLayout()
        self.setLayout(self.layout)

scroll_area = QScrollArea()
self.layout.addWidget(scroll_area)

viewport = QWidget()
scroll_area.setWidget(viewport)
viewport_layout = QGridLayout()
viewport.setLayout(viewport_layout)

for i in range(10):
    button = QPushButton(f"Button {i+1}")
    viewport_layout.addWidget(button, i // 3, i % 3)

scroll_area.setWidgetResizable(True)
scroll_area.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
scroll_area.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

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