Python使用requests时遇到Failed to establish a new connection

Python使用requests时，开启太多的connection会遇到这样一个错误

requests.exceptions.ConnectionError: HTTPConnectionPool(host='xxxx', port=xxxx):
    Max retries exceeded with url: /xxxx (Caused by NewConnectionError
    ('<requests.packages.urllib3.connection.HTTPConnection object at 0x29b44d0>:
    Failed to establish a new connection:
    [Errno 99] Cannot assign requested address',))

在短时间使用多次requests.post

修改如下

requests..get("http://...", headers={'Connection':'close'})
requests..post("http://...", headers={'Connection':'close'})

Python使用requests時遇到Failed to establish a new connection