Python PyQt program - Yes or No buttons

Python PyQt Widgets: Exercise-2 with Solution

Write a Python program that builds an application with two buttons "Yes" and "No" using PyQt. When the user clicks a button, display a message box with the corresponding choice.

From doc.qt.io:

QApplication Class: The QApplication class manages the GUI application's control flow and main settings.

QMainWindow Class: The QMainWindow class provides a main application window.

QPushButton: The push button, or command button, is perhaps the most commonly used widget in any graphical user interface. Push (click) a button to command the computer to perform some action, or to answer a question. Typical buttons are OK, Apply, Cancel, Close, Yes, No and Help.

QMessageBox Class: The QMessageBox class provides a modal dialog for informing the user or for asking the user a question and receiving an answer.

QVBoxLayout Class: The QVBoxLayout class lines up widgets vertically.

QWidget: The QWidget class is the base class of all user interface objects.

Sample Solution:

Python Code:

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QMessageBox, QVBoxLayout, QWidget
class YesNoApp(QMainWindow):
    def __init__(self):
        super().__init__()

        # Set the window properties (title and initial size)
        self.setWindowTitle("Pushbutton widgets (Yes or No)?")
        self.setGeometry(100, 100, 400, 200)  # (x, y, width, height)

        # Create a central widget for the main window
        central_widget = QWidget()
        self.setCentralWidget(central_widget)

        # Create QPushButton widgets for "Yes" and "No"
        yes_button = QPushButton("Yes")
        no_button = QPushButton("No")

        # Connect button clicks to corresponding methods
        yes_button.clicked.connect(self.show_yes_message)
        no_button.clicked.connect(self.show_no_message)

        # Create a layout for the central widget and add the buttons
        layout = QVBoxLayout()
        layout.addWidget(yes_button)
        layout.addWidget(no_button)

        # Set the layout for the central widget
        central_widget.setLayout(layout)

    def show_yes_message(self):
        QMessageBox.information(self, "Choice", "You chose 'Yes'.")

    def show_no_message(self):
        QMessageBox.information(self, "Choice", "You chose 'No'.")

def main():
    app = QApplication(sys.argv)
    window = YesNoApp()
    window.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

Explanation:

In the exercise above -

• Import the necessary modules.
• Create a "QMainWindow" named YesNoApp.
• Set the window's title and initial size.
• Create a central widget and set it as the central widget of the main window.
• Create "QPushButton" widgets for "Yes" and "No."
• Connect the button clicks to methods "show_yes_message()" and "show_no_message()", which will display message boxes with the corresponding choice when the buttons are clicked.
• Create a 'QVBoxLayout' for the central widget, add the buttons to it, and set it as the layout for the central widget.
• The "show_yes_message()" and "show_no_message()" methods use 'QMessageBox.information' to display message boxes with the user's choice.
• In the main function, we create the PyQt application, create an instance of the "YesNoApp" class, show the window, and run the application's event loop.

Output:

Flowchart:

Python Code Editor:

Previous: Display Hello, PyQt!.
Next: Simple text editor.