Why is host aborting connection?

Your client is now correct - you want to open the socket send the data, receive the reply and then close the socket.

The error original error was caused by the server closing the socket after it sent the first response which caused the client to receive a connection closed message when it tried to send the second message on the same connection.

However, I still don't understand what's going on. Isn't this just opening and closing the socket a bunch of times?

Yes. This is acceptable, if not the highest performance way of doing things.

Shouldn't there be time limitations to that (you shouldn't be able to open a socket so soon after closing it)?

You can open a client socket as quickly as you like as every time you open a socket you will get a new local port number, meaning that the connections won't interfere. In the server code above, it will start a new thread for each incoming connection.

There are 4 parts to every IP connection (source_address, source_port, destination_address, destination_port) and this quad (as it is known) must change for ever connection. Everything except source_port is fixed for a client socket so that is what the OS changes for you.

Opening server sockets is more troublesome - if you want to open a new server socket quickly, your

server.bind(('', 2727))

Above then you need to read up on SO_REUSEADDR.