Although I'm still studying the language, finally I managed to create a program that actually does something I need. The need arose from a gene list I was given, made up by Entrez Gene IDs. I need to annotate it, but in a form that wasn't able to be produced by the usual functional annotation tools I have. Actually it could have been done, but what I needed was to make something that I could automate.

Part of the job could have done by simply using DAVID to fetch Entrez Gene ID, Gene name and symbol, chromsome and cytoband, plus some Gene Ontology terms I needed. However, I took the chance to start using the language, and also to add other fields that I couldn't obtain in other ways. It's been a painful experience, but it worked. Right now it's tremendously hackish but I think I'll probably improve it in the next days. I'll post the source once it has a reasonable level of decency.