change text of lineEdit when a radio button is selected in pyqt

Question

I have two radioButtons in the form made using qt designer, i am now programming in pyqt. i wish to change the text of lineEdit to "radio 1" when radioButton 1 is selected and "radio 2" when the radioButton 2 is selected. how can I achieve this?

Solution

Here's a simple example. Each QRadioButton is connected to it's own function. You could connect them both to the same function and manage what happens through that, but I thought best to demonstrate how the signals and slots work.

For more info, take a look at the PyQt4 documentation for new style signals and slots. If connecting multiple signals to the same slot it's sometimes useful to use the .sender() method of a QObject, although in the case of QRadioButton it's probably easier to just check the .isChecked() method of your desired buttons.

import sys
from PyQt4.QtGui import QApplication, QWidget, QVBoxLayout, \
    QLineEdit, QRadioButton

class Widget(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)

        self.widget_layout = QVBoxLayout()

        self.radio1 = QRadioButton('Radio 1')
        self.radio2 = QRadioButton('Radio 2')
        self.line_edit = QLineEdit()

        self.radio1.toggled.connect(self.radio1_clicked)
        self.radio2.toggled.connect(self.radio2_clicked)

        self.widget_layout.addWidget(self.radio1)
        self.widget_layout.addWidget(self.radio2)
        self.widget_layout.addWidget(self.line_edit)
        self.setLayout(self.widget_layout)

    def radio1_clicked(self, enabled):
        if enabled:
            self.line_edit.setText('Radio 1')

    def radio2_clicked(self, enabled):
        if enabled:
            self.line_edit.setText('Radio 2')


if __name__ == '__main__':
  app = QApplication(sys.argv)
  widget = Widget()
  widget.show()

  sys.exit(app.exec_())