pyqt有关问题：TypeError: 'sip.methoddescriptor' object is not callable

pyqt问题：TypeError: 'sip.methoddescriptor' object is not callable
用pyqt4的qt设计师做了个主窗口，然后放了个按钮，弄了个槽：点按钮后，窗口退出

然后：pyuic4 -o test.py test.ui

写了个测试脚本：
from PyQt4.QtGui import *  
from PyQt4.QtCore import *  
import sys  
import test2  
   
class TestDlg(QDialog, test2.Ui_MainWindow):  
  def __init__(self, parent=None):  
  super(TestDlg, self).__init__(parent)  
  self.setupUi(self)  
app = QApplication(sys.argv)  
dialog = TestDlg()  
dialog.show()  


执行报错：
Traceback (most recent call last):
  File "F:\Python26\Lib\site-packages\PyQt4\test919.py", line 11, in <module>
  dialog = TestDlg()
  File "F:\Python26\Lib\site-packages\PyQt4\test919.py", line 9, in __init__
  self.setupUi(self)
  File "F:\Python26\Lib\site-packages\PyQt4\test2.py", line 26, in setupUi
  MainWindow.setCentralWidget(self.centralwidget)
TypeError: 'sip.methoddescriptor' object is not callable

test.py 的内容是：
# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'test2.ui'
#
# Created: Fri Sep 21 12:52:53 2012
# by: PyQt4 UI code generator 4.9.4
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui

try:
  _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
  _fromUtf8 = lambda s: s

class Ui_MainWindow(object):
  def setupUi(self, MainWindow):
  MainWindow.setObjectName(_fromUtf8("MainWindow"))
  MainWindow.resize(195, 69)
  self.centralwidget = QtGui.QWidget(MainWindow)
  self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
  self.pushButton = QtGui.QPushButton(self.centralwidget)
  self.pushButton.setGeometry(QtCore.QRect(50, 10, 75, 23))
  self.pushButton.setObjectName(_fromUtf8("pushButton"))
  MainWindow.setCentralWidget(self.centralwidget)
  self.menubar = QtGui.QMenuBar(MainWindow)
  self.menubar.setGeometry(QtCore.QRect(0, 0, 195, 17))
  self.menubar.setObjectName(_fromUtf8("menubar"))
  MainWindow.setMenuBar(self.menubar)
  self.statusbar = QtGui.QStatusBar(MainWindow)
  self.statusbar.setObjectName(_fromUtf8("statusbar"))
  MainWindow.setStatusBar(self.statusbar)

  self.retranslateUi(MainWindow)
  QtCore.QObject.connect(self.pushButton, QtCore.SIGNAL(_fromUtf8("clicked()")), MainWindow.deleteLater)
  QtCore.QMetaObject.connectSlotsByName(MainWindow)

  def retranslateUi(self, MainWindow):
  MainWindow.setWindowTitle(QtGui.QApplication.translate("MainWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8))
  self.pushButton.setText(QtGui.QApplication.translate("MainWindow", "PushButton", None, QtGui.QApplication.UnicodeUTF8))


【注明】老是提示：TypeError: 'sip.methoddescriptor' object is not callable，这是个什么东东？


------解决方案--------------------
测试脚本写得。。。

Python code

from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import QWidget   
import sys   
import test2   
    
class TestDlg(QWidget):   
    def __init__(self, parent=None):   
        QtGui.QWidget.__init__(self , parent)
        self.ui = test2.Ui_MainWindow()
        self.setupUi(self)   
app = QApplication(sys.argv)   
dialog = TestDlg()   
dialog.show()  
sys.exit(app.exec_())