How to pass arguments to callback functions in PyQt

I have around 10 QAction (this number will vary in runtime) in a toolbar, which all will do same thing, but using different parameters. I am thinking to add parameter as an attribute to QAction object, and then, QAction's triggered signal will also send object's itself to the callback function, so that I could get required parameters for the function. I have actually 2 questions about this:

Can it be done?
Is there a better way of doing this?

Solution

You can send the action object itself using a signal mapper. However, it may be better to simply send an identifier and do all the work within the signal handler.

Here's a simple demo script:

from PyQt4 import QtGui, QtCore

class Window(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.mapper = QtCore.QSignalMapper(self)
        self.toolbar = self.addToolBar('Foo')
        self.toolbar.setToolButtonStyle(QtCore.Qt.ToolButtonTextOnly)
        for text in 'One Two Three'.split():
            action = QtGui.QAction(text, self)
            self.mapper.setMapping(action, text)
            action.triggered.connect(self.mapper.map)
            self.toolbar.addAction(action)
        self.mapper.mapped['QString'].connect(self.handleButton)
        self.edit = QtGui.QLineEdit(self)
        self.setCentralWidget(self.edit)

    def handleButton(self, identifier):
        if identifier == 'One':
            text = 'Do This'
        elif identifier == 'Two':
            text = 'Do That'
        elif identifier == 'Three':
            text = 'Do Other'
        self.edit.setText(text)

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window()
    window.resize(300, 60)
    window.show()
    sys.exit(app.exec_())