calculator GUI

import sys
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout, QPushButton, QLineEdit, QVBoxLayout

class SimpleCalculator(QWidget):
    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        self.input_line = QLineEdit(self)
        self.input_line.setAlignment(Qt.AlignRight)
        self.input_line.setReadOnly(True)

        buttons = [
            '7', '8', '9', '/',
            '4', '5', '6', '*',
            '1', '2', '3', '-',
            '0', 'C', '=', '+'
        ]

        grid_layout = QGridLayout()
        row, col = 0, 0

        for button_text in buttons:
            button = QPushButton(button_text, self)
            button.clicked.connect(lambda _, ch=button_text: self.buttonClicked(ch))
            grid_layout.addWidget(button, row, col)
            col += 1
            if col > 3:
                col = 0
                row += 1

        main_layout = QVBoxLayout()
        main_layout.addWidget(self.input_line)
        main_layout.addLayout(grid_layout)
        self.setLayout(main_layout)

        self.setGeometry(300, 300, 300, 400)
        self.setWindowTitle('Kalkulator Sederhana')
        self.show()

    def buttonClicked(self, buttonText):
        if buttonText == '=':
            try:
                result = eval(self.input_line.text())
                self.input_line.setText(str(result))
            except Exception as e:
                self.input_line.setText('Error')
        elif buttonText == 'C':
            self.input_line.clear()
        else:
            current_text = self.input_line.text()
            new_text = current_text + buttonText
            self.input_line.setText(new_text)

def main():
    app = QApplication(sys.argv)
    calculator = SimpleCalculator()
    sys.exit(app.exec_())

main()