title: How to show QProgressBar smoothly?
body: <p>I'm learning <code>Pyside QProgressBar</code> on MacOSX. When I use QProgressBar like following, it only indicate 0% or 100%. How to make a QProgressBar smoothly? Is there any way to do this?</p>
  
  <pre><code>from PySide.QtGui import QApplication, QProgressBar, QWidget
  from PySide.QtCore import QTimer
  import time
  
  app = QApplication([])
  pbar = QProgressBar()
  pbar.setMinimum(0)
  pbar.setMaximum(100)
  
  pbar.show()
  
  def drawBar():
      global pbar
      pbar.update()
  
  t = QTimer()
  t.timeout.connect(drawBar)
  t.start(100)
  
  for i in range(1,101):
      time.sleep(0.1)
      pbar.setValue(i)
  
  app.exec_()
  </code></pre>