Changing a socket to the blocking/non-blocking mode

By default, TCP sockets are placed in a blocking mode. This means the control is not returned to your program until some specific operation is complete. If you call the connect() API, the connection blocks your program until the operation is complete. On many occasions, you don't want to keep your program waiting forever, either for a response from the server or for any error to stop the operation. For example, when you write a web browser client that connects to a web server, you should consider a stop functionality that can cancel the connection process in the middle of this operation. This can be achieved by placing the socket in the non-blocking mode.

How to do it...

Let us see what options are available under Python. In Python, a socket can be placed in the blocking or non-blocking mode. In the non-blocking mode, if any call to API, for example, send() or recv(), encounters any problem, an error will be raised. However, in the blocking...