PYQT5实现一个简单的计算输出显示功能

PYQT5实现一个简单的计算输出显示功能
效果如下

下面是源代码，直接可以运行

import sys

from PyQt5.QtWidgets import *


class Form(QDialog):
    def __init__(self):
        super().__init__()
        self.browser = QTextBrowser()
        self.lineedit = QLineEdit()
        self.lineedit.selectAll()
        layout = QVBoxLayout()
        layout.addWidget(self.browser)
        layout.addWidget(self.lineedit)
        self.setLayout(layout)
        self.lineedit.setFocus()
        self.lineedit.returnPressed.connect(self.updateui)


        self.setWindowTitle('calculate')



    def updateui(self):
        try:
            text = self.lineedit.text()
            self.browser.append('%s = %s' % (text, eval(text)))
            self.lineedit.clear()
        except:
            self.browser.append('% is invalid!' % text)
app = QApplication(sys.argv)
form = Form()
form.show()
app.exec()