FTP transmission in Python

Python FTP transfers access to FTP. there are only two things: upload and download. Recently, a large number of files need to be downloaded from ftp in the project. then I tried to experiment with my ftp operation class, as shown in the following figure (PS: This section has a problem. do not copy and use it. refer to test your ftp class !)

import osfrom ftplib import FTP  class FTPSync():    def __init__(self, host, usr, psw, log_file):        self.host = host        self.usr = usr        self.psw = psw        self.log_file = log_file          def __ConnectServer(self):        try:            self.ftp = FTP(self.host)            self.ftp.login(self.usr, self.psw)            self.ftp.set_pasv(False)            return True        except Exception:            return False          def __CloseServer(self):        try:            self.ftp.quit()            return True        except Exception:            return False          def __CheckSizeEqual(self, remoteFile, localFile):        try:            remoteFileSize = self.ftp.size(remoteFile)            localFileSize = os.path.getsize(localFile)            if localFileSize == remoteFileSize:                return True            else:                return False        except Exception:            return None              def __DownloadFile(self, remoteFile, localFile):        try:            self.ftp.cwd(os.path.dirname(remoteFile))            f = open(localFile, 'wb')            remoteFileName = 'RETR ' + os.path.basename(remoteFile)            self.ftp.retrbinary(remoteFileName, f.write)                          if self.__CheckSizeEqual(remoteFile, localFile):                self.log_file.write('The File is downloaded successfully to %s' + '\n' % localFile)                return True            else:                self.log_file.write('The localFile %s size is not same with the remoteFile' + '\n' %localFile)                return False        except Exception:            return False          def __DownloadFolder(self, remoteFolder, localFolder):        try:            fileList = []            self.ftp.retrlines('NLST', fileList.append)            for remoteFile in fileList:                localFile = os.path.join(localFolder, remoteFile)                return self.__DownloadFile(remoteFile, localFile)        except Exception:            return False          def SyncFromFTP(self, remoteFolder, localFolder):        self.__DownloadFolder(remoteFolder, localFolder)        self.log_file.close()        self.__CloseServer()