在Python中实现请求的重试

Question

POST使用requests软件包发送请求时,如何实现5次,10秒间的重试次数.我找到了很多GET请求的例子,但事实并非如此post.

这就是我目前正在处理的问题,有时我会收到503错误.如果我得到一个错误的响应HTTP代码,我只需要实现重试.

for x in final_payload:
    post_response = requests.post(url=endpoint, data=json.dumps(x), headers=headers)

#Email me the error
if str(post_response.status_code) not in ["201","200"]:
        email(str(post_response.status_code))

Answer 1

您可以urllib3.util.retry结合使用模块requests来获得如下内容:

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

def retry_session(retries, session=None, backoff_factor=0.3, status_forcelist=(500, 502, 503, 504)):
    session = session or requests.Session()
    retry = Retry(
        total=retries,
        read=retries,
        connect=retries,
        backoff_factor=backoff_factor,
        status_forcelist=status_forcelist,
    )
    adapter = HTTPAdapter(max_retries=retry)
    session.mount('http://', adapter)
    session.mount('https://', adapter)
    return session

用法:

session = retry_session(retries=5)
session.post(url=endpoint, data=json.dumps(x), headers=headers)

注意:您还可以从Retry类继承并自定义重试行为和重试间隔.

Answer 2

我发现重试的默认行为不适用于 POST。为此需要添加method_whitelist，例如下面：

def retry_session(retries=5):
    session = Session()
    retries = Retry(total=retries,
                backoff_factor=0.1,
                status_forcelist=[500, 502, 503, 504],
                method_whitelist=frozenset(['GET', 'POST']))

    session.mount('https://', HTTPAdapter(max_retries=retries))
    session.mount('http://', HTTPAdapter(max_retries=retries))

    return session