python - 请求中的 URL 超出了最大重试次数

Question

我正在尝试获取 App Store > Business 的内容:

import requests
from lxml import html

page = requests.get("https://itunes.apple.com/in/genre/ios-business/id6000?mt=8")
tree = html.fromstring(page.text)

flist = []
plist = []
for i in range(0, 100):
    app = tree.xpath("//div[@class='column first']/ul/li/a/@href")
    ap = app[0]
    page1 = requests.get(ap)

当我尝试使用 (0,2) 的 range 时，它可以工作，但是当我将 range 放入 100s 显示此错误:

Traceback (most recent call last):
  File "/home/preetham/Desktop/eg.py", line 17, in <module>
    page1 = requests.get(ap)
  File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 55, in get
    return request('get', url, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 44, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 383, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 486, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/requests/adapters.py", line 378, in send
    raise ConnectionError(e)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='itunes.apple.com', port=443): Max retries exceeded with url: /in/app/adobe-reader/id469337564?mt=8 (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known)

Answer 1

只需使用 requests 功能:

import requests
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry


session = requests.Session()
retry = Retry(connect=3, backoff_factor=0.5)
adapter = HTTPAdapter(max_retries=retry)
session.mount('http://', adapter)
session.mount('https://', adapter)

session.get(url)

这将 GET URL 并在 requests.exceptions.ConnectionError 的情况下重试 3 次。 backoff_factor 将有助于在尝试之间应用延迟以避免在定期请求配额的情况下再次失败。

看看urllib3.util.retry.Retry ，它有很多选项可以简化重试。