pyzdb is described as 'lightweight database with Python syntax queries, using ZeroMQ. Designed for storing nested list and dict, it offers Python syntax queries instead of some variation of SQL'. There are four alternatives to pyzdb for a variety of platforms, including Linux, Mac, Windows, Android and BSD. The best alternative is PostgreSQL, which is both free and Open Source. Other great apps like pyzdb are SQLite (Free, Open Source), PlanetScale (Freemium) and Matisse (Paid).
PostgreSQL is a powerful, open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness.
SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is the most widely deployed SQL database engine in the world. The source code for SQLite is in the public domain.