Python database

[Brice Vissi?re]

Hi python friends,

I'm currently working on a data handling tool.

For internal storage, I'm looking for a 100% python database.

I have some constraints:
 + multi-platform
 + relational with built-in query system (SQL preferably)
 + built-in string functions
 + reliable
 + fast

I don't care about:
 + network access
 + concurracy control
 + transaction commit/rollback

One of the key feature I'm looking for is direct string handling in
queries: concatenation, substring extraction, stripping, justifying,
... all we can do with python strings.

My first thought was to use Gadfly. I've downloaded and installed it.
Now, I'm  investigating the documentation and examples to find string
capabilities of Gadfly, but at first look, it seems that it will not
fit to my needs.

My problem would be solved by using a database allowing user function
creation, but I don't know whether such a tool exists.

So, have you any idea of a db tool I should use ?

Thanks in advance.

Brice