ZetCode

PyQt QSpinBox

last modified July 9, 2020

PyQt QSpinBox tutorial shows how to work with QSpinBox widget.

Sources are available at PyQt-Examples repository. Visit Advanced PyQt5 e-book, read PyQt5 tutorial, or list all PyQt tutorials.

QSpinBox

QSpinBox is designed to handle integers and discrete sets of values. It allows the user to choose a value by clicking the up/down buttons or pressing up/down on the keyboard to increase/decrease the value currently displayed. The value can be typed in manually as well.

The range of the spin box is set with setRange or with setMinimum and setMaximum functions. The amount of step is specified with setSingleStep.

The valueChanged signal is emitted whenever the spin box's value is changed. The value function determines the current value.

PyQt QSpinBox example

The following is a simple example that uses QSpinBox.

spinbox.py
#!/usr/bin/python


from PyQt5.QtWidgets import (QWidget, QSpinBox, QHBoxLayout,
                             QLabel, QApplication)
import sys


class Example(QWidget):

    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):

        hbox = QHBoxLayout()

        sbox = QSpinBox(self)

        sbox.valueChanged.connect(self.updateLabel)

        self.label = QLabel('0', self)

        hbox.addWidget(sbox)
        hbox.addSpacing(15)
        hbox.addWidget(self.label)

        self.setLayout(hbox)

        self.setGeometry(300, 300, 350, 250)
        self.setWindowTitle('QSpinBox')
        self.show()

    def updateLabel(self, value):

        self.label.setText(str(value))


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

The value chosen from the QSpinBox is displayed in the adjacent QLabel.

sbox.valueChanged.connect(self.updateLabel)

When the user selects a different value, the valueChanged is emitted. We attach the updateLabel handler to the signal.

def updateLabel(self, value):

    self.label.setText(str(value))

In the updateLabel handler, we set the spin box's value to the label.

QSpinBox
Figure: QSpinBox

QSpinBox range, step, suffix

In the following example, we explore additional functionality of the QSpinBox.

spinbox2.py
#!/usr/bin/python


from PyQt5.QtWidgets import (QWidget, QSpinBox, QHBoxLayout,
                             QLabel, QApplication)
import sys


class Example(QWidget):

    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):

        hbox = QHBoxLayout()

        sbox = QSpinBox(self)
        sbox.setRange(0, 200)
        sbox.setSingleStep(5)
        sbox.setSuffix(' km')

        sbox.valueChanged.connect(self.updateLabel)

        self.label = QLabel('0', self)

        hbox.addWidget(sbox)
        hbox.addSpacing(15)
        hbox.addWidget(self.label)

        self.setLayout(hbox)

        self.setGeometry(300, 300, 350, 250)
        self.setWindowTitle('QSpinBox')
        self.show()

    def updateLabel(self, value):

        self.label.setText(str(value))


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

In the example, we set the range, step, and suffix of the spin box.

sbox = QSpinBox(self)
sbox.setRange(0, 200)
sbox.setSingleStep(5)
sbox.setSuffix(' km')

The range is set with setRange, the step with setSingleStep, and the suffix with setSuffix.

QSpinBox showing suffix
Figure: QSpinBox showing suffix

QSpinBox value

The value function returns the current value of the QSpinBox.

show_value.py
#!/usr/bin/python


from PyQt5.QtWidgets import (QWidget, QSpinBox, QHBoxLayout, QMessageBox,
                             QPushButton, QApplication, QSizePolicy)
import sys


class Example(QWidget):

    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):

        hbox = QHBoxLayout()

        self.sbox = QSpinBox(self)

        btn = QPushButton('Show', self)
        btn.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)
        btn.clicked.connect(self.showSpinboxValue)

        hbox.addWidget(self.sbox)
        hbox.addSpacing(15)
        hbox.addWidget(btn)

        self.setLayout(hbox)

        self.setGeometry(300, 300, 350, 250)
        self.setWindowTitle('QSpinBox')
        self.show()

    def showSpinboxValue(self):

        val = self.sbox.value()
        QMessageBox.information(self, 'Value', f'Value: {val}')


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

In the example, we have a spin box and a push button. Clicking on the button a message box is displayed; it shows the current value of the spin box.

def showSpinboxValue(self):

    val = self.sbox.value()
    QMessageBox.information(self, 'Value', f'Value: {val}')

We determine the current value with value and display it in the message box.

In this tutorial, we have worked with PyQt QSpinBox.

List all PyQt tutorials.