PyQt5 QSpinBox – Checking if children region is NULL or not

Last Updated : 19 May, 2020

In this article we will see how we can check if the children region of spin box is NULL or not, children region holds the combined region occupied by the spin box’s children. In order to do this we use childrenRegion method. If we delete all the children of the spin box then this property will return an empty region. In order to do this we use isNull method.

Syntax : children_region.isNull() Argument : It takes no argument Return : It returns bool

Below is the implementation

Python3 1==

# importing libraries
from PyQt5.QtWidgets import * 
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * 
from PyQt5.QtCore import * 
import sys


class Window(QMainWindow):

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

        # setting title
        self.setWindowTitle("Python ")

        # setting geometry
        self.setGeometry(100, 100, 600, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()

        # method for widgets
    def UiComponents(self):
        # creating spin box
        self.spin = QSpinBox(self)

        # setting geometry to spin box
        self.spin.setGeometry(100, 100, 250, 40)

        # setting range to the spin box
        self.spin.setRange(0, 999999)

        # setting prefix to spin
        self.spin.setPrefix("Prefix ")

        # setting suffix to spin
        self.spin.setSuffix(" Suffix")

        # getting the children region
        children_region = self.spin.childrenRegion()

        # creating a label
        label = QLabel(self)

        # setting geometry to the label
        label.setGeometry(100, 200, 200, 30)

        # checking if children region is null
        check = children_region.isNull()

        # setting text to the label
        label.setText("Children Region is NULL ? " + str(check))

# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()
window.spin.setFocus()
# start the app
sys.exit(App.exec())