Access Management - User/Pass specific to DB, not server?

[Sam Mangham]

I'm writing scientific software that outputs a large number of records to file, and want to switch to handling the output in SQL so it's easy to search and sort with some Python analysis code. I'm having a bit of difficulty understanding the way DB access is managed for user accounts, though.

What I want is to be able to programatically create databases with an arbitrary name, and have my analysis code access them without needing a user/password or with a fixed username/password specified when I create the DB. I'm not entirely sure how I'd achieve this, as from what I can tell database permissions are done on a user-account basis, rather than set by the database itself. This is awkward as I don't want to have to keep making alterations to the user accounts whenever I create a new DB, or run on a new machine, and it'd make distributing the software to collaborators a lot harder.

Is there any way to specify when you create a DB that it shouldn't require a password, or that it should accept connections from *any* user account. In addition, is there a default passwordless MySQL user account with no database permissions that I can connect as in my analysis code without needing the user to set it up?

(I did try using SQLite for this where all of these things were non-issues, but was advised MySQL had much better performance on the ~200gb files I'd be using)