Access to Databases ?
Question from a beginner. Is it possible to access built-in databases with Pythonista like Calendar etc and is it possible to create or set up new databases ?
No, the sandboxing security measures of iOS prevent you from accessing the calendar database and things like that directly (that's why you see a dialog before any app accesses the calendar). I'm considering to add a module for accessing calendar/contacts data, but without that, there's no way to do it.
As for setting up new databases, there is the <a href="http://omz-software.com/pythonista/docs/library/sqlite3.html">sqlite3 module</a> which allows you to create SQLite databases. This can be useful for learning SQL and for storing structured data for your scripts, but if I understand your question correctly, it won't help you with what you're trying to do.
Access to read/write calendar and other databases that are now exposed via various APIs would certainly be very useful so I would be in favour of modules to do so!