Python - How do i remove the window border? I have imported UI from Qt into Python and applied setWindowFlags

How to make this window Border-less (remove minimize/maximize/close)?

  1 import sys
  2 from PyQt4 import QtCore, QtGui
  3 from qt import Ui_MainWindow
  4 
  5 class StartQT4(QtGui.QMainWindow):
  6     def __init__(self, parent=None):
  7         QtGui.QWidget.__init__(self, parent)
  8         self.ui = Ui_MainWindow()
  9         self.ui.setupUi(self))
 10         
 11 if __name__ == "__main__":
 12     app = QtGui.QApplication(sys.argv)
 13     myapp = StartQT4()
 14     myapp.show()
 15     app.setWindowFlags(app.FramelessWindowHint) <<< does not working
 16     sys.exit(app.exec_())
 17