完整错误：

WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', NewConnectionError('<pip._vendor.urllib3.connection.HTTPConnection object at 0x0000021FA8A69FD0>: Failed to establish a new connection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。'))': http://mirrors.aliyun.com/pypi/simple/pytorch-nlp/
ERROR: Could not find a version that satisfies the requirement pytorch-nlp (from versions: none)
ERROR: No matching distribution found for pytorch-nlp

解决方案：开代理