Requirements for model (DTO) base class

[rafalkrupinski]

The model class binds two domains - Python and OpenAPI, and it should handle them explicitly.

In JSON:

• any valid Unicode string can be used as a key
• value can only be of one type (string, integer, float, array, object or null) at a time

In Python:

• all __dunder__ names are reserved, shouldn't put a dunder key in self.__dict__
• object methods names can't be used as field names.
• keywords cannot be used as field names
• values can be more than one type (str is also Iterable[str]), classes can be also list.

A model base class should:

• have minimal footprint of object method and fields
• support exporting to and importing from json/yaml compatible dict
• handle reserved names
• support object validation against OpenAPI schema

All model method could be class methods:

class MyModel(lapidary.Model):
   ...

obj=MyModel(...)
MyModel.to_dict(obj)
MyModel.from_dict(obj)
MyModel.validate(obj)