Simple web script

Basically I want to send information, say a string, to my website and then I want my website to write this information to a text file.

I'm using Python to send the info, and I've read about sending information via a socket, but how do I get my website to listen for this data? And what IP address do I send this data to if I want my website to receive it once this server is running?

Just ask me if something wasn't clear, I'm not even quite sure what I'm looking for hence why I can't just google it.