I created a program which listens to particular socket in python, however I ctrl+c'd script which resulted in .close() nor called, however how can I free the socket now.
The socket is closed when the process exits. The port it was using may hang around for a couple of minutes, that's normal, then it will disappear. If you need to re-use the port immediately, set SO_REUSEADDR before binding or connecting.
closing a previously opened socket