pyqt5实现简易计算器

以下是一个简单的 PyQt5 计算器实现：

from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, QGridLayout, QPushButton, QLineEdit
import sys

class Calculator(QMainWindow):

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

        # 设置窗口标题和大小
        self.setWindowTitle('Calculator')
        self.setFixedSize(240, 320)

        # 创建中心窗口和布局
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        self.central_layout = QVBoxLayout()
        self.central_widget.setLayout(self.central_layout)

        # 创建文本框和按钮
        self.display = QLineEdit()
        self.display.setReadOnly(True)
        self.central_layout.addWidget(self.display)

        self.buttons = []
        button_layout = QGridLayout()
        button_layout.setSpacing(5)
        for i in range(0, 10):
            button = QPushButton(str(i))
            button.clicked.connect(self.button_clicked)
            button_layout.addWidget(button, int((9-i)/3), (i-1)%3)
            self.buttons.append(button)

        self.add_button = QPushButton('+')
        self.add_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.add_button, 0, 3)

        self.sub_button = QPushButton('-')
        self.sub_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.sub_button, 1, 3)

        self.mul_button = QPushButton('*')
        self.mul_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.mul_button, 2, 3)

        self.div_button = QPushButton('/')
        self.div_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.div_button, 3, 3)

        self.dot_button = QPushButton('.')
        self.dot_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.dot_button, 3, 2)

        self.eq_button = QPushButton('=')
        self.eq_button.clicked.connect(self.button_clicked)
        button_layout.addWidget(self.eq_button, 3, 1)

        self.clear_button = QPushButton('C')
        self.clear_button.clicked.connect(self.clear_display)
        button_layout.addWidget(self.clear_button, 3, 0)

        self.central_layout.addLayout(button_layout)

    def button_clicked(self):
        sender = self.sender()
        if sender in self.buttons:
            self.display.setText(self.display.text() + sender.text())
        elif sender == self.dot_button:
            if '.' not in self.display.text():
                self.display.setText(self.display.text() + '.')
        elif sender == self.add_button:
            self.display.setText(self.display.text() + '+')
        elif sender == self.sub_button:
            self.display.setText(self.display.text() + '-')
        elif sender == self.mul_button:
            self.display.setText(self.display.text() + '*')
        elif sender == self.div_button:
            self.display.setText(self.display.text() + '/')
        elif sender == self.eq_button:
            try:
                result = eval(self.display.text())
                self.display.setText(str(result))
            except:
                self.display.setText('Error')

    def clear_display(self):
        self.display.setText('')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    calculator = Calculator()
    calculator.show()
    sys.exit(app.exec_())

这个计算器有基本的加减乘除、小数点和等于按钮，并且能够处理异常情况。运行这个程序将会出现一个简单的计算器界面。