import sys
from PyQt4 import QtGui
from PyQt4 import QtCore

#Icon继承了QtGui.QWidget这个类
class Icon(QtGui.QWidget):
    def __init__(self,parent=None):
        QtGui.QWidget.__init__(self,parent)

        self.setGeometry(300,300,250,150)
        self.setWindowTitle(‘Icon‘)
        self.setWindowIcon(QtGui.QIcon("1.png"))

app=QtGui.QApplication(sys.argv)
icon=Icon()
icon.show()
sys.exit(app.exec_())