退出程序并提示是否退出：

def quite(self,event):           #退出程序按钮
    reply = QtWidgets.QMessageBox.question(self,'程序',"是否退出程序", QtWidgets.QMessageBox.Yes |       QtWidgets.QMessageBox.No, QtWidgets.QMessageBox.No)
    if reply == QtWidgets.QMessageBox.Yes:
        event.accept()
    else:
        event.ignore()

清空文本框：

def clean1(self):                   #清空文本框
    self.textEdit.setText('')

选择要打开的文本：

def choose1(self):
    choose1_text = self.comboBox.currentText()
    print(choose1_text)
    if choose1_text == "分词":
        openfile_name, filetype = QtWidgets.QFileDialog.getOpenFileName(self,'選擇文件','',"All Files(*);;Text Files(*.txt)")
        with open(openfile_name,"r",encoding = "utf8") as file_read:
            con = file_read.readlines()
            #self.textEdit.setText(str(con))
            str1 = ""
            for line1 in con:
                #self.textEdit.setText(str(line1))
                #self.textEdit.setText("\n")
                seg_list = jieba.cut(line1,cut_all=False)
                line_seg = ' '.join(seg_list)



                str1 = str1 + line_seg
            self.textBrowser.setText(str(str1))
            print(str1)

显示下拉列表中显示的内容（combobox）

def choose2(self):
  

    choose3_text = self.comboBox_3.currentText()

居中显示窗口

def center(self):                        #居中显示窗口

    qr = self.frameGeometry()
    cp = QtWidgets.QDesktopWidget().availableGeometry().center()
    qr.moveCenter(cp)
    self.move(qr.topLeft())