How to catch exception MaxRetryError?

Question

I have a list of proxy addresses for which I want to connect the telegrams-bot. Proxies can be blocked over time or simply not work, this can be seen by the MaxRetryError error. But I can't catch an error. I have an error in logs. I want to catch an error and switch to another proxy server.

from telegram.ext import Updater

REQUEST_KWARGS = {
    'proxy_url': proxy_url,
    'urllib3_proxy_kwargs': {
        'retries': 0
    }
}

updater = Updater(token=TELEGRAM_TOKEN, request_kwargs=REQUEST_KWARGS)
queue = updater.start_polling(bootstrap_retries=0)

.....
raise MaxRetryError(_pool, url, error or ResponseError(cause))
telegram.vendor.ptb_urllib3.urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='api.telegram.org', port=443): Max retries exceeded with url: /bot877422445:AAEGBD0D9stJKMF6PvCClChx8MNMGX-vLEY/deleteWebhook (Caused by ProxyError('Cannot connect to proxy.', NewConnectionError('<telegram.vendor.ptb_urllib3.urllib3.connection.VerifiedHTTPSConnection object at 0x11572df98>: Failed to establish a new connection: [Errno 61] Connection refused')))
......
telegram.error.NetworkError: urllib3 HTTPError HTTPSConnectionPool(host='api.telegram.org', port=443): Max retries exceeded with url: /bot877422445:AAEGBD0D9stJKMF6PvCClChx8MNMGX-vLEY/deleteWebhook (Caused by ProxyError('Cannot connect to proxy.', NewConnectionError('<telegram.vendor.ptb_urllib3.urllib3.connection.VerifiedHTTPSConnection object at 0x11572df98>: Failed to establish a new connection: [Errno 61] Connection refused')))

2019-07-26 16:07:38,553 - telegram.ext.dispatcher - CRITICAL - stopping due to exception in another thread

Answer 1

This way ?

try:
  updater = Updater(token=TELEGRAM_TOKEN, request_kwargs=REQUEST_KWARGS)
  queue = updater.start_polling(bootstrap_retries=0)
except MaxRetryError:
  #doSomething