Python numeric keypad with PyQt - Button grid

Last update on December 21 2024 07:44:52 (UTC/GMT +8 hours)

Write a Python program to create push buttons in a grid where each button represents a numeric keypad. Use PyQt module.

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.

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

QGridLayout Class: The QGridLayout class lays out widgets in a grid.

QPushButton Class: The QPushButton widget provides a command button.

Sample Solution:

Python Code:

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QGridLayout, QPushButton
class NumericKeypadApp(QMainWindow):
    def __init__(self):
        super().__init__()

        # Set the window properties (title and initial size)
        self.setWindowTitle("Numeric Keypad")
        self.setGeometry(100, 100, 300, 400)  # (x, y, width, height)

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

        # Create a QGridLayout for arranging the buttons
        grid_layout = QGridLayout()

        # Create numeric keypad buttons (0-9)
        for i in range(10):
            button = QPushButton(str(i))
            button.clicked.connect(lambda _, ch=i: self.on_button_click(ch))  # Use a lambda to pass the value
            grid_layout.addWidget(button, i // 3, i % 3)

        # Create a layout for the central widget
        layout = QGridLayout()
        layout.addLayout(grid_layout, 0, 0)

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

    def on_button_click(self, value):
        # Handle button click event (for demonstration, print the clicked value)
        print(f"Button {value} clicked!")

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

if __name__ == "__main__":
    main()

Explanation:

In the exercise above -

Import the necessary modules.
Create a "QMainWindow" named "NumericKeypadApp" with a central widget.
Set the window's title and initial size.
Create a "QGridLayout" named grid_layout to arrange the numeric keypad buttons in a grid.
Create numeric keypad buttons (0-9) in a loop and connect their click events to the on_button_click method, passing the button's value as an argument.
The "on_button_click()" method handles button click events. For demonstration purposes, it prints the clicked value.
Arrange the numeric keypad buttons using the "QGridLayout".
In the main function, we create the PyQt application, create an instance of the "NumericKeypadApp" class, show the window, and run the application's event loop.

Output:

Button 7 clicked!
Button 1 clicked!
Button 0 clicked!
Button 1 clicked!
Button 5 clicked!

Flowchart:

Python Code Editor:

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