pyqt5 ms级获取时间小工具

代码：

from PyQt5 import QtCore, QtGui, QtWidgets
from datetime import datetime  //注意添加

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(444, 491)
        MainWindow.setStyleSheet("background-color: rgb(255, 255, 255);")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.textBrowser = QtWidgets.QTextBrowser(self.centralwidget)
        self.textBrowser.setGeometry(QtCore.QRect(20, 0, 401, 321))
        font = QtGui.QFont()
        font.setFamily("幼圆")
        font.setPointSize(14)
        self.textBrowser.setFont(font)
        self.textBrowser.setObjectName("textBrowser")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(60, 340, 321, 81))
        font = QtGui.QFont()
        font.setFamily("幼圆")
        font.setPointSize(14)
        self.pushButton.setFont(font)
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 444, 23))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.pushButton.clicked.connect(self.slot1)  //修改self
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "ms级时间精度测试工具"))   
        self.pushButton.setText(_translate("MainWindow", "点击获取时间"))

    def slot1(self):
        time1=datetime.now()
        time2=str(time1)
        print(time1)
        self.textBrowser.append('当前标准时间:')  //需要用append ，不然会覆盖掉获取的数据
        self.textBrowser.append(time2)

import sys
if __name__ == '__main__':
    app=QtWidgets.QApplication(sys.argv)
    MainWindow=QtWidgets.QMainWindow()
    ui=Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())