pyqt信号和槽传递额外参数

from PyQt4.QtCore import *from PyQt4.QtGui import *class MyForm(QMainWindow):    def __init__(self, parent=None):        super(MyForm, self).__init__(parent)        button1 = QPushButton('Button 1')        button2 = QPushButton('Button 1')        button1.clicked.connect(lambda: self.on_button(1))        button2.clicked.connect(lambda: self.on_button(2))        layout = QHBoxLayout()        layout.addWidget(button1)        layout.addWidget(button2)        main_frame = QWidget()        main_frame.setLayout(layout)        self.setCentralWidget(main_frame)    def on_button(self, n):        print('Button {0} clicked'.format(n))if __name__ == "__main__":    import sys    app = QApplication(sys.argv)    form = MyForm()    form.show()    app.exec_()
解释一下，on_button是怎样处理从两个按钮传来的信号。我们使用lambda传递按钮数字给槽，也可以传递任何其他东西---甚至是按钮组件本身（假如，槽打算把传递信号的按钮修改为不可用）
第2个方法是使用functools里的partial函数。
[python] view plain copyprint?button1.clicked.connect(partial(self.on_button, 1))  button2.clicked.connect(partial(self.on_button, 2))  
button1.clicked.connect(partial(self.on_button, 1))button2.clicked.connect(partial(self.on_button, 2))
哪个办法好一点？这个属于风格的问题。个人观点，喜欢lambda，条理清楚，而且灵活。
《Rapid GUI Program with Python and QT》 P143例子。
[python] view plain copyprint?from PyQt4.QtCore import *  from PyQt4.QtGui import *  from functools import partial  import sys    class Bu1(QWidget):          def __init__(self, parent=None):          super(Bu1, self).__init__(parent)          #水平盒式布局          layout = QHBoxLayout()          #显示          self.lbl = QLabel('no button is pressed')          #循环5个按钮          for i in range(5):              but = QPushButton(str(i))              layout.addWidget(but)              #信号和槽连接              but.clicked.connect(self.cliked)                        #使用封装，lambda          but = QPushButton('5')          layout.addWidget(but)          but.clicked.connect(lambda: self.on_click('5'))          #使用个who变量，结果不正常，显示 False is pressed          #but.clicked.connect(lambda who="5": self.on_click(who))                    #使用封装，partial函数          but = QPushButton('6')          layout.addWidget(but)          but.clicked.connect(partial(self.on_click, '6'))                    layout.addWidget(self.lbl)          #设置布局          self.setLayout(layout)                #传递额外参数         def cliked(self):          bu = self.sender()          if isinstance(bu, QPushButton):              self.lbl.setText('%s is pressed' % bu.text())          else:              self.lbl.setText('no effect')      def on_click(self, n):          self.lbl.setText('%s is pressed' % n)                if __name__ == '__main__':              app = QApplication(sys.argv)      bu =Bu1()      bu.show()      app.exec_()  
from PyQt4.QtCore import *from PyQt4.QtGui import *from functools import partialimport sysclass Bu1(QWidget):      def __init__(self, parent=None):        super(Bu1, self).__init__(parent)        #水平盒式布局        layout = QHBoxLayout()        #显示        self.lbl = QLabel('no button is pressed')        #循环5个按钮        for i in range(5):            but = QPushButton(str(i))            layout.addWidget(but)            #信号和槽连接            but.clicked.connect(self.cliked)                    #使用封装，lambda        but = QPushButton('5')        layout.addWidget(but)        but.clicked.connect(lambda: self.on_click('5'))        #使用个who变量，结果不正常，显示 False is pressed        #but.clicked.connect(lambda who="5": self.on_click(who))                #使用封装，partial函数        but = QPushButton('6')        layout.addWidget(but)        but.clicked.connect(partial(self.on_click, '6'))                layout.addWidget(self.lbl)        #设置布局        self.setLayout(layout)            #传递额外参数       def cliked(self):        bu = self.sender()        if isinstance(bu, QPushButton):            self.lbl.setText('%s is pressed' % bu.text())        else:            self.lbl.setText('no effect')    def on_click(self, n):        self.lbl.setText('%s is pressed' % n)            if __name__ == '__main__':            app = QApplication(sys.argv)    bu =Bu1()    bu.show()    app.exec_()