Question

In this sample of code:

from PyQt4.QtGui import QDialog, QPushButton, QRadioButton, QHBoxLayout, QApplication, QButtonGroup
import sys

class Form(QDialog):
    def __init__(self, parent=None):
        super(Form, self).__init__(parent=None)

        button = QPushButton('Button')
        self.radiobutton1 = QRadioButton('1')
        self.radiobutton2 = QRadioButton('2')
        #self.group = QButtonGroup()
        #self.group.addButton(self.radiobutton1)
        #self.group.addButton(self.radiobutton2)       
        #self.group.setExclusive(False)

        layout = QHBoxLayout()
        layout.addWidget(button)
        layout.addWidget(self.radiobutton1)
        layout.addWidget(self.radiobutton2)
        self.setLayout(layout)

        button.clicked.connect(self.my_method)

    def my_method(self):
        self.radiobutton1.setChecked(False)
        self.radiobutton2.setChecked(False)

app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()

When the button clicked I expect the selected radioButton to be unchecked, but that never happens. If I uncomment the comment lines and run the code, then I can uncheck radioButtons. But another problem occurs. Because the group is not exclusive, I can set both radioButtons checked something that must not happens.

What should I do to be able to unckeck the buttons while only one button at a time can be selected?

Answer 1

This feels like cheating, but it works:

import sys
import PyQt4.QtGui as QtGui

class Form(QtGui.QDialog):
    def __init__(self, parent=None):
        super(Form, self).__init__(parent)

        button = QtGui.QPushButton('Button')
        button.clicked.connect(self.my_method)

        self.radiobutton1 = QtGui.QRadioButton('1')
        self.radiobutton2 = QtGui.QRadioButton('2')

        layout = QtGui.QHBoxLayout()
        layout.addWidget(button)
        layout.addWidget(self.radiobutton1)
        layout.addWidget(self.radiobutton2)
        self.setLayout(layout)

        self.group = QtGui.QButtonGroup()
        self.group.addButton(self.radiobutton1)
        self.group.addButton(self.radiobutton2)       

    def my_method(self):
        self.group.setExclusive(False)        
        self.radiobutton1.setChecked(False)
        self.radiobutton2.setChecked(False)
        self.group.setExclusive(True)

app = QtGui.QApplication(sys.argv)
form = Form()
form.show()
app.exec_()

As you’ve pointed out, when self.group.setExclusive(False) is set, you can untoggle both radio buttons.

And when self.group.setExclusive(True), only one radio button can be set.

So my_method simply calls self.group.setExclusive(False) so it can unset both radio buttons, then resets self.group.setExclusive(True).

---

PS. I think parent should not be set to None on this line:

super(Form, self).__init__(parent = None)

since if a non-trivial parent is sent to Form, you would probably want to pass that parent on to QDialog.__init__.