PyQt:eg4

import sys
from PyQt4 import QtCore
from PyQt4 import QtGui

class Form(QtGui.QDialog):

    def __init__(self, parent=None):
        super(Form, self).__init__(parent)

        self.dial = QtGui.QDial()
        self.dial.setNotchesVisible(True)
        self.spinbox = QtGui.QSpinBox()

        self.layout = QtGui.QHBoxLayout()
        self.layout.addWidget(self.dial)
        self.layout.addWidget(self.spinbox)
        self.setLayout(self.layout)

        self.connect(self.dial, QtCore.SIGNAL("valueChanged(int)"), self.spinbox.setValue)
        self.connect(self.spinbox, QtCore.SIGNAL("valueChanged(int)"), self.dial.setValue)
        self.setWindowTitle("Signals and Slots")

        self.connect(self.dial, QtCore.SIGNAL("valueChanged(int)"),
            self.spinbox, QtCore.SLOT("setValue(int)"))
        self.connect(self.spinbox, QtCore.SIGNAL("valueChanged(int)"),
            self.dial, QtCore.SLOT("setValue(int)"))

app = QtGui.QApplication(sys.argv)
form = Form()
form.show()
app.exec_()