rearrange Exception

import re

import sys

import traceback

from time import sleep

import requests

from time import sleep

from bs4 import BeautifulSoup

from urllib3.exceptions import ResponseError

from requests.exceptions import ConnectionError

logging.basicConfig(

    format="[%(asctime)s.%(msecs)03d] - %(levelname)s - %(message)s",

    datefmt='%Y/%b/%d %H:%M:%S',

login = requests.session()

CONNECTED = 10001

CONNECTION_TIMEOUT = 10002

NEED_LOGIN = 10003

def load_config():

   with open('./config.json') as f:

      config = json.load(f)

def test_network(url):

   try:

   with login.get(url, timeout=10, allow_redirects=False) as test:

      if 300 > test.status_code >= 200:

             return CONNECTED, None

         return None

      elif test.status_code == 302:

             content = login.get(test.headers['Location'], timeout=10).content

             soup_login = BeautifulSoup(content, 'html5lib')

             if 'CAS' not in soup_login.title.string:

                logging.warning('Not connected to a SUSTC network')

                return CONNECTED, None

             else:

                return NEED_LOGIN, re.search(r'window\.location = \'(.*)\';', soup_login.text).group(1)

         return test.headers['Location']

      else:

             logging.warning('Recieved status code {code}, consider updating \'captive_portal_server\''.format(code=test.status_code))

             return CONNECTION_TIMEOUT, None

   except requests.RequestException:

       return CONNECTION_TIMEOUT, None

         raise ResponseError("Invalid status code {code}".format(code=test.status_code))

def main():

   logging.info('Program started.')

      os.chdir(os.path.dirname(sys.argv[0]))  # To read config in the same directory

   except OSError:

      pass

   config = load_config()

   times_retry_login = config['max_times_retry_login']

   test_url = config['captive_portal_server']

   logging.info('Configurations successfully imported.')

   while True:

   while times_retry_login >= 0:

      logging.info('Checking network status...')

      status, rem_link = test_network(test_url)

      if status == CONNECTION_TIMEOUT:

         logging.info('Connection FAILED. Try again in ' + str(config['interval_retry_connection']) + ' sec.')

         times_retry_login -= 1

      elif status == CONNECTED:

      try:

         link = test_network(test_url)

         if not link:

            logging.info('You are already logged in.')

         break

      elif status == NEED_LOGIN:

            return

         else:

            content = login.get(link, timeout=10).content

            soup_login = BeautifulSoup(content, 'html5lib')

            if 'CAS' not in soup_login.title.string:

               logging.warning('Not connected to a SUSTC network')

               return

            logging.info('You are offline. Starting login...')

            rem_link = re.search(r'window\.location = \'(.*)\';', soup_login.text).group(1)

            hostname = 'http://enet.10000.gd.cn:10001/sz/sz112/'

         url = hostname + rem_link

            service = hostname + rem_link

         success, err = do_login(url, config['username'], config['password'])

            success, err = do_login(service, config['username'], config['password'])

            if err:

            times_retry_login -= 1

               logging.error('Error occurred: ' + err.text)

               times_retry_login -= 1

            elif success:

               logging.info('Login successful')

            break

               return

      except ConnectionError as err:

         logging.warn('Connection FAILED. Try again in ' + str(config['interval_retry_connection']) + ' sec.')

         times_retry_login -= 1

      if times_retry_login > 0:

      # If keep trying to login too many times, it may trigger security alarm on the CAS server

      logging.info('Try again in {time} sec. {attempt} attempt(s) remaining.'.format(time=config['interval_retry_connection'], attempt=times_retry_login))

      else:

         logging.info('Attempts used up. The program will quit.')

         sys.exit(-1)

      sleep(config['interval_retry_connection'])

   logging.info('Online.')

   sys.exit(0)

   logging.error('Attempts used up. The program will quit.')

if __name__ == '__main__':

   try:

      main()

   except ResponseError as err:

      logging.error('{msg}, consider updating \'captive_portal_server\''.format(msg=str(err)))

   except Exception as e:

      logging.error("".join(traceback.format_exc()))