from PyQt4 import QtGui, QtCore
import sys
 
class Window(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self) #import all widgets and core functions
        self.resize(200,200)
        self.setWindowTitle('First Window')
 
app = QtGui.QApplication(sys.argv)
main = Window()
main.show()
sys.exit(app.exec_()) #freeze screen