Python：检查电子邮件时代码随机崩溃

Question

This code:

import imaplib, re
import os
import time

conn = imaplib.IMAP4_SSL("imap.gmail.com", 993)
conn.login("ddd@ddd.com", "ddd")

while(True):
    unreadCount = re.search("UNSEEN (\d+)", conn.status("INBOX", "(UNSEEN)")[1][0]).group(1)
    print unreadCount

    if int(unreadCount) > 20:
      os.system('heroku restart --app warm-beach-203')
        #os.system('ls')
        #print "Restarting server...."

    time.sleep(60)

Output:

0
1
0
0
0
0
0
4
Traceback (most recent call last):
  File "gmail.py", line 10, in <module>
    unreadCount = re.search("UNSEEN (\d+)", conn.status("INBOX", "(UNSEEN)")[1][0]).group(1)
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 704, in status
    typ, dat = self._simple_command(name, mailbox, names)
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 1059, in _simple_command
    return self._command_complete(name, self._command(name, *args))
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 889, in _command_complete
    typ, data = self._get_tagged_response(tag)
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 990, in _get_tagged_response
    self._get_response()
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 907, in _get_response
    resp = self._get_line()
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 1000, in _get_line
    line = self.readline()
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/imaplib.py", line 1170, in readline
    char = self.sslobj.read(1)
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/ssl.py", line 136, in read
    return self._sslobj.read(len)
socket.error: [Errno 60] Operation timed out

I dont understand why it crashes randomly.

Answer 1

The final error line is descriptive: the connection is timing out before the IMAP operation completes. It could be simply that Gmail is running slowly. If that's the case, you could try extending the timeout like so:

import socket
socket.setdefaulttimeout(15)  # In seconds

where 15 is the value you've experimentally determined works well for you.