问将所有选项卡操作替换为在QPlainTextEdit小部件中插入四个空格

EN

s= text_edit.toPlainText()
s= s.replace('\t', '    ')

from PyQt5.QtWidgets import *
import sys

class Wind(QWidget):
    def __init__(self):
        super().__init__()
        self.setupUI()

    def setupUI(self):
        self.setGeometry(300,300, 300,500)
        self.show()

        vb_layout= QVBoxLayout(self)

        text_edit= QTextEdit(self)

        # This method sets tab width in pixels
        text_edit.setTabStopWidth(8)

        vb_layout.addWidget(text_edit)
        self.setLayout(vb_layout)

def main():
    app= QApplication(sys.argv)
    w = Wind()
    exit(app.exec_())


if __name__ == '__main__':
    main()

 def keyPressEvent (self, oEvent):
    if oEvent.key () == Qt.Key_Tab:
        oEvent = QKeyEvent (QEvent.KeyPress
            , Qt.Key_Space
            , Qt.KeyboardModifiers(oEvent.nativeModifiers())
            , "    ")
    super().keyPressEvent (oEvent)