Simple PySide tutorial, #2: signals and slots

Second tutorial for PySide, this time focusing on Qt's signals and slots system, trying to provide a simple example of how they can be chained together to provide simpler code.

# Written by Robin Burchell  
# No licence specified or required, but please give credit where it's due, and please let me know if this helped you.
# Feel free to contact with corrections or suggestions.
#
# We're using PySide, Nokia's official LGPL bindings.
# You can however easily use PyQt (Riverside Computing's GPL bindings) by commenting these and fixing the appropriate imports.
from PySide.QtCore import *
from PySide.QtGui import *
#from PyQt4 import *
#from PyQt4.QtCore import *
#from PyQt4.QtGui import *
import sys

class MyMainWindow(QWidget):
 def __init__(self):
  QWidget.__init__(self, None)

  vbox = QVBoxLayout()

  # Let's create two sliders widgets.
  #  http://doc.trolltech.com/4.6/qslider.html
  sone = QSlider(Qt.Horizontal)
  vbox.addWidget(sone)

  stwo = QSlider(Qt.Horizontal)
  vbox.addWidget(stwo)

  # Link the first slider to the second.
  # Think of this as an event and listener system - a signal is an event, and it can have multiple listeners.
  # A slot is a listener to an event.
  #
  # Signals are generally used whenever an action occurs which might require a reaction, or feedback - for example,
  # a user clicking on a button, or a slider value changing.
  #
  # A signal can provide one (or more) parameters, which can then be used in the corresponding slot(s).
  #
  # In this example, we're linking the valueChanged signal to setValue on the second slider, meaning that whenever the
  # first slider is moved, the second slider will move with it.
  #
  # This might look strange when compared with the .NET and other typical methods of doing it, but it
  # really is much more natural and easier to express.
  # See also:
  # http://doc.trolltech.com/4.6/signalsandslots.html
  self.connect(sone, SIGNAL("valueChanged(int)"), stwo, SLOT("setValue(int)"));

  # Set the layout on the window: this means that our button will actually be displayed.
  self.setLayout(vbox)

if __name__ == '__main__':
 app = QApplication(sys.argv)
 w = MyMainWindow()
 w.show()
 app.exec_()
 sys.exit()