Cerberus VS marshmallow

I was expecting this to validate the configuration files are also valid for their use cases, not just valid JSON, TOML, etc.

If you're looking for that and Python is your jam, the library cerberus[0] is very good at it.

[0]: https://github.com/pyeve/cerberus

I wrote scrapy-test as a proof of concept for validating live pages for scrapy spiders if you're looking for some reference but if you're not using scrapy I'd recommend just adding validation tests using data validation tools like cerberus which is super underrated. I cover popular data validation techniques on this short blog I wrote if you want to learn more.

Other than that, have you looked into testing scrapers? Since scrapers are working with highly dynamic data writing good tests is quite a challange. For example, for parser monitoring using cerberus is a very cool tool which allows you to define loose requirements like "phone number should always be 9 numbers" etc.

Somehow get a serializer going for your database models. I used marshmallow and flask-marshmallow

Uses a robust data validation library: validating payloads is a complex business. Your data validation library must handle optional and required properties, string formats like ISO dates and UUIDs (both dates and UUIDs are string types in OpenAPI), and strict vs loose type validation (should a string pass as an integer if it can be casted?). Also, in the case of Python, you need to make sure 1 and 0 don’t pass for True and False when it comes to boolean properties. In my experience, the best data validation libraries in the Python ecosystem are pydantic and marshmallow. From the above-mentioned libraries, flasgger and flask-smorest work with marshmallow.

I also came across things like Marsmallow and Blueprints, but don't know what these are, still reading about this as I write.

Pydantic is a data validation library, marshmallow is a data validation library. None of the other libraries in the list of pydantic alternatives is a data validation library.

I have been working on a package that is very similar in concept to marshmallow (https://marshmallow.readthedocs.io), but which adds a versioning mechanism to track changes in object structure across time, allowing you to migrate objects between different versions.

Either using meta programming: https://github.com/marshmallow-code/marshmallow/issues/585

You might be surprised how much I agree - I recently opened an issue there hoping to discuss something like this (still awaiting response). https://github.com/marshmallow-code/marshmallow/issues/2000

Marshmallow

I created a shallow fork of everyone's favourite marshmallow, to work around some performance issues while dumping data. The performance gain I measured is around 45%, but since it's a bad idea to rely on one's own testing, I was hoping that there are some folks here who use marshmallow in their projects, and who would be willing to try it out. Doubly so if your project has some unit tests in it, to confirm that nothing is broken due to my patches.

I was looking at https://github.com/marshmallow-code/marshmallow That's a nice library to use to parsing?