Passing values to custom 'slot' functions (pyqt)

[Richie]

Hi,

Can I first say thanks to all who read my newb questions and helped me out, much appreciated.

Quick pyqt question:

mywindow has a button on it. I want to run the clicked_function when clicked. This works

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), clicked_function)

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), clicked_function)

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But if I want to click the button and pass 'foo' to the clicked_function, I thought I would be able to use

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), clicked_function('foo'))

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), clicked_function('foo'))

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This brings up an 'argument of incorrect type' error. So how can I pass a value to the function? I thought I might try...

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), pre_clicked_function)
 
def pre_clicked_function():
    clicked_function('foo')

QtCore.QObject.connect(mywindow.somebutton, QtCore.SIGNAL("clicked()"), pre_clicked_function)

def pre_clicked_function():
    clicked_function('foo')

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But this is far from streamlined! Any better ideas?

[hkvm]

Hi!

Use functools.partial, it can take a function and "pre-fill" some or all its arguments, like this:

import functools
#...
self.connect(mywindow.somebutton, SIGNAL("clicked()"), functools.partial(clicked_function, "foo"))

import functools
#...
self.connect(mywindow.somebutton, SIGNAL("clicked()"), functools.partial(clicked_function, "foo"))

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[mayowa]

Hi,

Another way to do this would be to use lambda:

self.connect(mywindow.somebutton, SIGNAL("clicked()"), (lambda p="foo" : clicked_function(p)))

self.connect(mywindow.somebutton, SIGNAL("clicked()"), (lambda p="foo" : clicked_function(p)))

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