在建立连接前设置非阻塞，会报错[Errno 119] EINPROGRESS

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)addr = socket.getaddrinfo(host, port)[0][-1]sock.setblocking(False)  # 非阻塞sock.connect(addr)

改成先连接，后设置，即可

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)addr = socket.getaddrinfo(host, port)[0][-1]sock.connect(addr)sock.setblocking(False)  # 非阻塞