问pyqt4 table表格怎么用事件过滤器 让点击表格单元格才有效 而不是在表格周围就会被触发呢？

from PyQt4 import QtCore, QtGui
class QueueManagerScreen(QtGui.QDialog):
    def __init__(self, parent=None):
        super(QueueManagerScreen, self).__init__(parent)
        self.createItems()
        self.currentTable=[]
        
    def createItems(self):
        self.queue_area1 = QtGui.QTabWidget() 
        self.queue_area1.setMovable(True)
        tab_bar = tabBar(self)
        self.queue_area1.setTabBar(tab_bar)
        self.tab = Widget(self)
        self.tab.snaddr="00"
        self.tab.spaddr="00"
        self.OutLayout=QtGui.QHBoxLayout()
        self.Label=QtGui.QGroupBox(u"布局")
        self.table = self.QueueTableNormal()###表格
        self.TabLayout = QtGui.QGridLayout()
        self.TabLayout.addWidget(self.table,0,0,1,1)
        self.Label.setLayout(self.TabLayout)
        self.OutLayout.addWidget(self.Label)
        self.currentTable.append(self.table)
        self.table.update()
        self.tab.setLayout(self.OutLayout)
        self.queue_area1.insertTab(0, self.tab, u'屏1')
        self.queue_area1.setStyleSheet("QTabWidget::tab-bar{alignment:left;border:1px solid red}") 
        
    def QueueTableNormal(self):#表格
        QTableWidget=QtGui.QTableWidget()
        QTableWidget.setEditTriggers(QtGui.QTableWidget.NoEditTriggers)
        QTableWidget.horizontalScrollBar().setContextMenuPolicy(QtCore.Qt.NoContextMenu)
        QTableWidget.verticalScrollBar().setContextMenuPolicy(QtCore.Qt.NoContextMenu)
        QTableWidget.setColumnCount(1)
        QTableWidget.setRowCount(1)
        # QTableWidget.setMouseTracking(True)
        QTableWidget.installEventFilter(self)##安装事件过滤
        QTableWidget.setStyleSheet("QTableWidget::item:selected{border:1px solid #1E90FF; background-color:transparent} " )
        return QTableWidget  
         
   def eventFilter(self, obj, event):##想通过事件过滤只有左点击表格内单元格才能生效
        if obj == self.table:
            if event.type() == QtCore.QEvent.MouseButtonPress and event.mouse() == QtCore.Qt.LeftButton:
                self.close()
                return True
        return QtCore.QObject.eventFilter(self, obj, event) 
          
   def mousePressEvent(self, mouseEvent):
        self.currentTable[self.tableidx].mousePressEvent(mouseEvent)
        if mouseEvent.button() == QtCore.Qt.RightButton:
            print('右点击')
        elif mouseEvent.button() == QtCore.Qt.LeftButton:
            print('左点击 ')