example code:
# -*- coding: utf-8 -*-
import sys
from PySide import QtCore, QtGui
import time

class Highlighter(QtGui.QSyntaxHighlighter):

    def __init__(self, parent, mode):
        QtGui.QSyntaxHighlighter.__init__(self, parent)
        self.tstamp=time.time()

    def highlightBlock(self, text):
        text=self.document()


if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    python = QtGui.QTextEdit()
    python.setWindowTitle('python')
    hl=Highlighter(python.document(),"python")
    python.show()
    app.exec_()

when add 'text=self.document()' ,the application exit crash,if use other code
instead of them ,exit the application Ok.