models.py

from .models import Model, ModelRegistry

class User(Model):
    __yaml__ = 'user.yaml'

john = User(**kw)

user.yaml

title: User
description: >
  User profile with common fields used on various sites

fields:
  - name: name
    title: Name
    type: string
    length: 80
    required: 1
  - name: second
    title: Second Name
    type: string
    length: 80
  - name: bday
    title: Birthday
    type: date
    required: 1
    widget: date
  - name: about
    title: About
    description: >
      Some text about you here is welcome
    db_name: about
    widget:
      name: wysiwyg
      theme: simple
  - name: friends
    type: reference
    reference_model: User
    desription: >
      List of your friends on site