问如何修复HTTP错误503:服务不可用错误

EN

amazon = bottlenose.Amazon(AMAZON_ACCESS_KEY,AMAZON_SECRET_KEY,AMAZON_ASSOC_TAG)
response = amazon.ItemLookup(ItemId='B007OZNUCE')

Traceback (most recent call last):
  File "exazapi.py", line 37, in <module>
    response = amazon.ItemLookup(ItemId='B007OZNUCE')
  File "C:\Python\lib\site-packages\bottlenose\api.py", line 274, in __call__
    {'api_url': api_url, 'cache_url': cache_url})
  File "C:\Python\lib\site-packages\bottlenose\api.py", line 235, in _call_api
    return urllib2.urlopen(api_request, timeout=self.Timeout)
  File "C:\Python\lib\urllib\request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "C:\Python\lib\urllib\request.py", line 531, in open
    response = meth(req, response)
  File "C:\Python\lib\urllib\request.py", line 641, in http_response
    'http', request, response, code, msg, hdrs)
  File "C:\Python\lib\urllib\request.py", line 569, in error
    return self._call_chain(*args)
  File "C:\Python\lib\urllib\request.py", line 503, in _call_chain
    result = func(*args)
  File "C:\Python\lib\urllib\request.py", line 649, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 503: Service Unavailable

#import all the required modules
import re
import csv
import sys
import warnings
from urllib.request import urlopen
from bs4 import BeautifulSoup
from requests_html import HTMLSession

import bottlenose
#from amazon.api import AmazonAPI

AMAZON_ACCESS_KEY='xxx'
AMAZON_SECRET_KEY='xxx'
AMAZON_ASSOC_TAG='xxx'


#ignore warnings
if not sys.warnoptions:
    warnings.simplefilter("ignore")


amazon = bottlenose.Amazon(AMAZON_ACCESS_KEY,AMAZON_SECRET_KEY,AMAZON_ASSOC_TAG)
response = amazon.ItemLookup(ItemId='B007OZNUCE')
print (amazon)
print(response)