toastedmarshmallow-models

:fire:toastedmarshmallow-models:fire:: Create Serializable Class Models

Inspired by Marshmallow Models <https://github.com/douglas-treadwell/marshmallow-models>_ and by ORM libraries.

The Toasted Marshmallow Models package makes it easy to define serializable classes based on the ultra fast serialization that Toasted Marshmallow <https://github.com/lyft/toasted-marshmallow>_ provides.

Installing toastedmarshmallow-models

.. code-block:: bash

pip install toastedmarshmallow-models

Using Toasted Marshmallow Models

Using Toasted Marshmallow Models in an existing class requires your class to inherit the Model class and specify the relevant Marshmallow fields. For example:

.. code-block:: python

from marshmallow import fields
from toastedmarshmallow_models import Model

class Entity(Model):  # Inherit Model
    # Define Marshmallow fields
    id = fields.Integer()
    name = fields.String()

    def __init__(self, id, name):
        self.id = id
        self.name = name

How it works

The Toasted Marshmallow Models package makes it easy to dump and load models.

Dump methods:

.. code-block:: python

entity = Entity(id=1, name='John Doe')

print(entity.to_dict())
# {"id": 1, "name": "John"}

print(entity.to_json())
# '{"id": 1, "name": "John"}'

Load Methods:

.. code-block:: python

entity = Entity.from_dict({"id": 1, "name": "John"}) # creates an Entity instance

entity = Entity.from_json('{"id": 1, "name": "John"}') # creates an Entity instance

Features

Validation:

.. code-block:: python

entity = Entity(id='i-am-not-a-valid-int', name='John Doe')

entity.validate()  # throws marshmallow.ValidationError if not valid

Get validation errors:

.. code-block:: python

entity = Entity(id='i-am-not-a-valid-int', name='John Doe')

entity.get_validation_errors()  # returns dict(id=['Not a valid integer.'])

Nested Models:

.. code-block:: python

class ChildEntity(Model):
    name = fields.String()

    def __init__(self, name: str):
        self.name = name


class ParentEntity(Model):
    name = fields.String()
    # Use NestedModel to define parent-child relationships
    children = fields.Nested(NestedModel(ChildEntity), many=True)

    def __init__(self, name: str, children: List[ChildEntity]):
        self.children = children
        self.name = name

Self Referencing Model:

.. code-block:: python

class Employee(Model):
    name = fields.String()
    # Use SelfReferencingModel to define self-referencing relationships
    subordinates = fields.Nested(SelfReferencingModel('Employee'), many=True, allow_none=True)

    def __init__(self, name: str, subordinates: List['Employee'] = None):
        self.subordinates = subordinates
        self.name = name