详解Python Requests库中的重试策略

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

retries = Retry(
    total=5,  # 总重试次数
    backoff_factor=1,  # 指数退避因子
    status_forcelist=[500, 502, 503, 504],  # 指定哪些状态码触发重试
    allowed_methods=frozenset(['GET', 'POST']),  # 允许重试的HTTP方法
)

adapter = HTTPAdapter(max_retries=retries)

pythonCopy code
session = requests.Session()
session.mount('http://', adapter)
session.mount('https://', adapter)

url = "http://httpbin.org/status/500"
response = session.get(url)

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

def request_with_retry(url, max_retries=5, backoff_factor=1, status_forcelist=None):
    if status_forcelist is None:
        status_forcelist = [500, 502, 503, 504]
        
    session = requests.Session()
    retries = Retry(total=max_retries,
                    backoff_factor=backoff_factor,
                    status_forcelist=status_forcelist,
                    method_whitelist=["GET", "POST"])
    adapter = HTTPAdapter(max_retries=retries)
    session.mount('http://', adapter)
    session.mount('https://', adapter)
    
    try:
        response = session.get(url)
        response.raise_for_status()  # 如果请求返回的是4XX, 5XX响应码，将引发HTTPError异常
        return response
    except requests.exceptions.HTTPError as e:
        print(f"HTTP Error: {e}")
    except requests.exceptions.ConnectionError as e:
        print(f"Connection Error: {e}")
    except requests.exceptions.Timeout as e:
        print(f"Timeout Error: {e}")
    except requests.exceptions.RequestException as e:
        print(f"Request Exception: {e}")

url = "http://httpbin.org/status/500"
response = request_with_retry(url)

if response:
    print(response.text)