Python PyQt program - Yes or No buttons

Last update on December 21 2024 07:44:53 (UTC/GMT +8 hours)

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:

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