Python套接字连接错误/异常处理？

Question

因此，我使用下面的循环效果很好，直到它碰到某些仅会导致连接错误的主机。 不幸的是，它没有跳过这些实例，而是导致脚本崩溃。 我知道要捕获并避免此异常，最好是在try：except块中通过麻烦的语句（serveroutput = tn.read_until（b'STARTTLS'）） 。 我可以做到，但是我不确定如何捕获错误并告诉它继续进行。 如果添加一个中断，它将中断循环并导致脚本无论如何都提前停止。 我如何继续遍历j？ 我听说我可以使用“ continue”作为继续迭代的方法，但是我是否在这里捕捉到了正确的异常？

我的代码：

def getServers():
    fp = open("mailserverdata.csv", "r")
    pt = from_csv(fp)
    fp.close()
    domains = txt_domains.get(1.0, 'end').splitlines()
    symbols = txt_symbols.get(1.0, 'end').splitlines()
    for x in range(len(domains)):
        #Start Get MX Record
        answers = dns.resolver.query(str(domains[x]), 'MX')
        #End Get MX Record
        #Start Get Employees
        if symbols[x]!='':
            xml = urllib.request.urlopen('https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.stocks%20where%20symbol%3D%22'+symbols[x]+'%22&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys')
            dom = parse(xml)
            numemployees = dom.getElementsByTagName('FullTimeEmployees')
            if len(numemployees)!=0:
                numemployees = numemployees[0].firstChild.nodeValue
        else:
            numemployees = 0
        #End Get Employees
        j=0
        tlsbool = 'N'
        verified = 'N'
        for rdata in answers:
            #Start Trim Domains
            output = str(rdata.exchange)
            output = output[:len(output)-1]
            print(output)
            #End Trim Domains
            #Start Telnet
            tn = telnetlib.Telnet(output,25)
            tn.write(b'ehlo a.com\r\n')
            serveroutput = tn.read_until(b'STARTTLS')
            checkvar = "STARTTLS"
            for checkvar in serveroutput:
                tlsbool = 'Y'
                break
            #End Telnet
            #Start verification
            if output.find(domains[x])>-1:
                verified = 'Y'
            #End verification
            if j==0:
                pt.add_row([domains[x],output,tlsbool,numemployees,verified])
            else:
                pt.add_row(['',output,tlsbool,'',verified])
            j = j + 1
    txt_tableout.delete(1.0, 'end')
    txt_tableout.insert('end',pt)
    root.ptglobal = pt

尝试捕获代码：

try:
    serveroutput = tn.read_until(b'STARTTLS')
except SocketError as e:
    if e.errno != errno.ECONNRESET:
        raise # Not error we are looking for
    pass # Handle error here.

全栈错误：

Traceback (most recent call last):
  File "C:\Python34\lib\tkinter\__init__.py", line 1487, in __call__
    return self.func(*args)
  File "C:\Users\kylec\Desktop\Data Motion\Mail Server Finder\mailserverfinder.py", line 58, in getServers
    serveroutput = tn.read_until(b'STARTTLS')
  File "C:\Python34\lib\telnetlib.py", line 317, in read_until
    self.fill_rawq()
  File "C:\Python34\lib\telnetlib.py", line 526, in fill_rawq
    buf = self.sock.recv(50)
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host

更新：

我尝试了以下代码，但收到以下错误。

代码：尝试：serveroutput = tn.read_until（b'STARTTLS'），除了tn.ConnectionsResetError：继续

错误：

AttributeError: 'Telnet' object has no attribute 'ConnectionsResetError'

Answer 1

最终对我有用的是对@ user3570335建议的修改。

try:
    serveroutput = tn.read_until(b'STARTTLS')
except Exception as e:
    tlsbool = '?'