用python制作个论文下载器(图形化界面)

class runthread(QtCore.QThread):
 # 通过类成员对象定义信号对象
 _signal = QtCore.pyqtSignal(str)
 
 def __init__(self, titleText, saveText):
  super(runthread, self).__init__()
  self.titleText = titleText
  self.saveText = saveText
 
 def __del__(self):
  self.wait()
 
 def run(self):
  if self.titleText == '' or self.saveText == '': # 如果为空
   self._signal.emit('EMPTY')
   return
  headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:84.0) Gecko/20100101 Firefox/84.0',
     'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
     'Accept-Language':'zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2',
     'Accept-Encoding':'gzip, deflate, br',
     'Connection':'keep-alive',
     'Upgrade-Insecure-Requests':'1'}
  if not self.titleText.endswith('.txt'): # 如果不为目录（即单篇论文标题）
   self._signal.emit('SEARCH')
   downUrl = search_article(self.titleText)
   if downUrl == '': # 如果搜索结果为空
    self._signal.emit('NULL')
    return
   else:
    try:
     self._signal.emit('DOWNLOAD')
     res = requests.get(downUrl, headers=headers, stream=True)
     fileSize = int(res.headers['Content-Length'])
     print(fileSize)
     savedSize = 0
     saveName = change_title(self.titleText)
     with open('%s/%s.pdf'%(self.saveText,saveName), 'wb') as f:
      for chunk in res.iter_content(chunk_size=1024):
       if chunk:
        f.write(chunk)
        savedSize += len(chunk)
        progress = int(savedSize/fileSize*100)
        self._signal.emit('PRO-%d'%progress)
     self._signal.emit('SUCCESS')   
    except:
     self._signal.emit('FAILED')
  else:
   paperList = read_file(self.titleText)
   if paperList == '':
    self._signal.emit('FILEWRONG')
   else:
    error = [] # 用于记录失败的论文
    self._signal.emit('BATCH-%d'%len(paperList))
    for i in range(len(paperList)):
     try:
      downUrl = search_article(paperList[i])
      print(downUrl)
      pdf = download_article(downUrl)
      saveName = change_title(paperList[i])
      with open('%s/%s.pdf'%(self.saveText,saveName), 'wb') as f:
       f.write(pdf)
     except:
      error.append(paperList[i])
     self._signal.emit('NUM-%d'%(i+1)) 
    with open('./errors.txt', 'w') as f:
     for e in error:
      f.write(e+'\n')
    self._signal.emit('COMPLETED-%d'%len(error))

def call_backrun(self, msg):
 if msg == 'EMPTY':
  QtWidgets.QMessageBox.warning(self.centralwidget, '警告', '标题或目录为空！')
 if msg == 'SEARCH':
  self.runButton.setVisible(False)
  self.quitButton.setVisible(False)
  self.searchLabel.setVisible(True)
 if msg == 'NULL':
  self.runButton.setVisible(True)
  self.quitButton.setVisible(True)
  self.searchLabel.setVisible(False)
  QtWidgets.QMessageBox.information(self.centralwidget, '提示', '未搜到相应论文！')
 if msg == 'DOWNLOAD':
  self.searchLabel.setVisible(False)
  self.progressBar.setVisible(True)
  self.progressBar.setFormat('%%p')
  self.progressBar.setValue(0)
 if 'PRO' in msg:
  pro = int(msg.split('-')[-1])
  self.progressBar.setValue(pro)
 if msg == 'SUCCESS':
  self.progressBar.setVisible(False)
  self.runButton.setVisible(True)
  self.quitButton.setVisible(True)
  self.titleEdit.setText('')
  QtWidgets.QMessageBox.information(self.centralwidget, '提示', '论文下载完毕！')
 if msg == 'FAILED':
  self.progressBar.setVisible(False)
  self.runButton.setVisible(True)
  self.quitButton.setVisible(True)
  QtWidgets.QMessageBox.information(self.centralwidget, '提示', '论文下载失败！')
 if msg == 'FILEWRONG':
  QtWidgets.QMessageBox.information(self.centralwidget, '提示', '论文列表错误！')
 if 'BATCH' in msg:
  sumNumber = msg.split('-')[-1]
  self.runButton.setVisible(False)
  self.quitButton.setVisible(False)
  self.progressBar.setVisible(True)
  self.progressBar.setFormat('【%v/'+sumNumber+'】')
  self.progressBar.setMinimum(0)
  self.progressBar.setMaximum(int(sumNumber))
  self.progressBar.setValue(0)
 if 'NUM' in msg:
  num = int(msg.split('-')[-1])
  self.progressBar.setValue(num)
 if 'COMPLETED' in msg:
  errorNum = int(msg.split('-')[-1])
  self.progressBar.setVisible(False)
  self.runButton.setVisible(True)
  self.quitButton.setVisible(True)
  self.titleEdit.setText('')
  QtWidgets.QMessageBox.information(self.centralwidget, '提示', '论文下载完毕！\n（%d个失败）'%errorNum)

def run(self):
 titleText = self.titleEdit.text()
 saveText = self.saveEdit.text()
 # 创建线程
 self.runthread = runthread(titleText, saveText)
 # 连接信号
 self.runthread._signal.connect(self.call_backrun) # 进程连接回传到GUI的事件
 # 开始线程
 self.runthread.start()