hide splitter handle

import sys

from PySide6.QtWidgets import QApplication, QMainWindow, QSplitter, QWidget


class MainWindow(QMainWindow):
    def __init__(self, parent: QWidget | None = None) -> None:
        super().__init__(parent)

        splitter: QSplitter = QSplitter(self)

        splitter.addWidget(QWidget(self))
        splitter.addWidget(QWidget(self))
        splitter.addWidget(QWidget(self))

        splitter.handle(1).hide()
        assert splitter.handle(1).isHidden() and not splitter.handle(1).isVisible()
        splitter.handle(1).setHidden(True)
        assert splitter.handle(1).isHidden() and not splitter.handle(1).isVisible()
        splitter.handle(1).setVisible(False)
        assert splitter.handle(1).isHidden() and not splitter.handle(1).isVisible()

        self.setCentralWidget(splitter)


if __name__ == '__main__':
    QApplication(sys.argv)
    s: MainWindow = MainWindow()
    s.show()
    QApplication.exec()