# requests.exceptions.ConnectionError: HTTPConnectionPool(host='proxy.example.com', port=8080): 超过最大重试次数 (由ProxyError('无法连接到代理。', ConnectTimeoutError('<urllib3.connection.HTTPConnection object at 0x...>: 无法建立新连接：[Errno 110] 连接超时'))引起)

- **ID:** `python/requests-connectionerror-proxy-connection-timeout`
- **领域:** python
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

由于网络问题或代理宕机，代理服务器不可达。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 3.x | active | — | — |

## 解决方案

1. **Check proxy server status and network connectivity** (85% 成功率)
   ```
   telnet proxy.example.com 8080
# If fails, contact proxy administrator or use a different proxy
   ```
2. **Use a direct connection without proxy** (70% 成功率)
   ```
   response = requests.get('http://target.com')  # remove proxies parameter
   ```

## 无效尝试

- **Increasing the proxy timeout in the code** — If the proxy is down, longer timeout does not help. (80% 失败率)
- **Using a different port on the same proxy** — The proxy server itself is unreachable, not the port. (90% 失败率)