centos7中python3.6报错ModuleNotFoundError: No module named '_ssl' 或者 Max retries exceeded with url: / (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.",))
如果在运行爬虫时报此错:requests.exceptions.SSLError:HTTPSConnectionPool(host='www.baidu.com',port=443):Maxretriesexceededwithurl