import socket from ftplib import FTP true, false = 1, 0 def isFTPSiteUp(site): try: FTP(site).quit() except(socket.error): return false return true def refineFTPList(list): new_list = [] for site in list: if isFTPSiteUp(site): new_list.append(site) return new_list sites = ['ftp.cdrom.com', 'ftp.redhat.com', 'ftp.ska143blah.com'] working_sites = refineFTPList(sites) print working_sites