title: name unicode not defined python3
body: <p>i have been trying to run this code
  this is the error</p>
  <pre><code> File &quot;C:/hari/Academics/python/py programs/gui qt4/book/calculator.py&quot;, line 27, in updateUi
      text = unicode(self.lineedit.text(),'utf-8')
  NameError: name 'unicode' is not defined
  </code></pre>
  <p>the code :</p>
  <pre><code>from __future__ import division
  from math import *
  from PyQt4.QtGui import *
  from PyQt4.QtCore import *
  import sys
  
  class Form(QDialog):
      def __init__(self,parent =None):
      super(Form,self).__init__(parent)
      self.browser =QTextBrowser()
      self.lineedit =QLineEdit(&quot;type an exp&quot;)
      self.lineedit.selectAll()
      layout=QVBoxLayout()
      layout.addWidget(self.browser)
      layout.addWidget(self.lineedit)
      self.setLayout(layout)
      self.lineedit.setFocus()
      self.connect(self.lineedit, SIGNAL(&quot;returnPressed()&quot;), self.updateUi)
      self.setWindowTitle(&quot;Calculate&quot;)
  def updateUi(self):
      try:
          text = unicode(self.lineedit.text())
          print(type(text))
          self.browser.append(text+&quot; = &lt;b&gt;&quot;+eval(text)+&quot;&lt;/b&gt;&quot; )
  
      except:
          self.browser.append(&quot;&lt;font color=red&gt;&quot;+ text + &quot; is invalid&lt;/font&gt;&quot;)
  app=QApplication(sys.argv)
  f=Form()
  f.show()
  app.exec_()
  </code></pre>