QT designer ui in python PyQT - event

import sys
from PyQt4.QtGui import QApplication, QDialog
from PyQt4 import uic

# a sample event listener
def handle():
    print "clicked"
    # get text in QTextEdit to display in QLabel
    ui.label.setText("hello " + ui.textEdit.toPlainText())

app = QApplication(sys.argv)
window = QDialog()
# dialog.ui is an xml file generated by QT designer
ui = uic.loadUi("dialog.ui")

# set text of QTextEdit
ui.textEdit.setText("hello")
# set text with HTML
ui.textEdit.setHtml("bolditalic")
# connect an event to a listener
ui.pushButton.clicked.connect(handle)

ui.show()

sys.exit(app.exec_())


QT .UI XML

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Dialog</class>
 <widget class="QDialog" name="Dialog">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Dialog</string>
  </property>
  <widget class="QDialogButtonBox" name="buttonBox">
   <property name="geometry">
    <rect>
     <x>30</x>
     <y>240</y>
     <width>341</width>
     <height>32</height>
    </rect>
   </property>
   <property name="orientation">
    <enum>Qt::Horizontal</enum>
   </property>
   <property name="standardButtons">
    <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
   </property>
  </widget>
  <widget class="QLabel" name="label">
   <property name="geometry">
    <rect>
     <x>10</x>
     <y>10</y>
     <width>200</width>
     <height>13</height>
    </rect>
   </property>
   <property name="text">
    <string>TextLabel</string>
   </property>
  </widget>
  <widget class="QTextEdit" name="textEdit">
   <property name="geometry">
    <rect>
     <x>10</x>
     <y>30</y>
     <width>231</width>
     <height>50</height>
    </rect>
   </property>
  </widget>
  <widget class="QPushButton" name="pushButton">
   <property name="geometry">
    <rect>
     <x>10</x>
     <y>110</y>
     <width>75</width>
     <height>23</height>
    </rect>
   </property>
   <property name="text">
    <string>PushButton</string>
   </property>
  </widget>
 </widget>
 <resources/>
 <connections>
  <connection>
   <sender>buttonBox</sender>
   <signal>accepted()</signal>
   <receiver>Dialog</receiver>
   <slot>accept()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>248</x>
     <y>254</y>
    </hint>
    <hint type="destinationlabel">
     <x>157</x>
     <y>274</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>buttonBox</sender>
   <signal>rejected()</signal>
   <receiver>Dialog</receiver>
   <slot>reject()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>316</x>
     <y>260</y>
    </hint>
    <hint type="destinationlabel">
     <x>286</x>
     <y>274</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>