typedecorator | A decorator-based implementation of type checks | Architecture library

I recently started using SQLAlchemy for a database application I'm working on. Things were going fine until I required relationships. I have looked at the documentation and found out what to do. However, it only works when my models are in the same .py file. That is a bit messy to me so I tried to separate them out into their own model_name.py files. eg:

frame_model.py:

I use class model for each table with method for every sql operation with SQLAlchemy.

I install pgp_sym_encrypt and pgp_sym_decrypt with the extension of PostgreSQL

I am using the custom type form this answer, which is quite similar to the one recommended in the SqlAlchemy documentation, let me reproduce it here for a self-contained question:

I want to set a column default value for my custom column type.

Currently I have this:

I'm trying to create a Type converter on SQLAlchemy that takes a BIGINTEGER from the database, and converts it to a Base64 value.

The problem is that, for some reasons, the value coming from the database is not an int, but a decimal.Decimal. I suspect this is linked to the BigInteger class I use (from the MySQL dialect instead of the BIGINT from SQLAlchemy because I need to set the unsigned parameter).

Any idea how to get the value from the database as int and not as decimal.Decimal ?

Here's my current implementation:

I want to create decorators, which will change type of returning value:

I have created a TypeDecorator based off of the SQLAlchemy example that converts between a 32-character hex string and the BINARY database column in which the UUID is stored: