Advice on scripting a "whitewashed" and downsized development db from main db
What you're referring to is usually called Test Data Management. There are several commercial solutions, e.g. IBM Optim Test Data Management (disclosure: I work for IBM, but don't speak for them). I'm not aware of any free products that can perform that function, so I'm afraid you'll have to stick to your Python scripts unless you have deep pockets.

On a side note, I would suggest using the same database platform, i.e. PostgreSQL, for both production and development -- it will probably save you some troubleshooting time later.