objectfactory

objectfactory is a python package to easily implement the factory design pattern for object creation, serialization, and polymorphism

objectfactory.base

base module

implements abstract base classes for objectfactory

class objectfactory.base.FieldABC(default=None, key=None, required=False, allow_none=True)

Bases: ABC

abstract base class for serializable field

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

abstract marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.base.SerializableABC

Bases: ABC

abstract base class for serializable object

abstract deserialize(body: dict)

deserialize model from dictionary

Parameters:

body – serialized data to load into object

abstract serialize(include_type: bool = True, use_full_type: bool = True) → dict

serialize model to dictionary

Parameters:

• include_type – if true, type information will be included in body

• use_full_type – if true, the fully qualified path with be specified in body

Returns:

serialized object as dict

objectfactory.factory

factory module

implements serializable object factory

class objectfactory.factory.Factory(name)

Bases: object

factory class for registering and creating serializable objects

create(body: dict, object_type: ~typing.Type[~objectfactory.factory.T] = <class 'objectfactory.serializable.Serializable'>) → T

create object from dictionary

Parameters:

• body – serialized object data

• object_type – (optional) specified object type

Raises:

TypeError – if the object is not an instance of the specified type

Returns:

deserialized object of specified type

register(serializable: Serializable)

decorator to register class with factory

Parameters:

serializable – serializable object class

Returns:

registered class

objectfactory.factory.create(body: dict, object_type: ~typing.Type[~objectfactory.factory.T] = <class 'objectfactory.serializable.Serializable'>) → T

create object from dictionary with the global factory

Parameters:

• body – serialized object data

• object_type – (optional) specified object type

Raises:

TypeError – if the object is not an instance of the specified type

Returns:

deserialized object of specified type

objectfactory.factory.register(serializable: Serializable)

decorator to register class with the global factory

Parameters:

serializable – serializable object class

Returns:

registered class

objectfactory.field

field module

implements serializable fields

class objectfactory.field.Boolean(default=None, key=None, required=False, allow_none=True)

Bases: Field

serializable field for boolean data

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.DateTime(default=None, key=None, date_format=None, required=False, allow_none=True)

Bases: Field

serializable field for datetime data

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• date_format – date format to use (defaults to iso)

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.Enum(enum, default=None, key=None, required=False, allow_none=True, by_value=False)

Bases: Field

serializable field for enumerated data

Parameters:

• enum – enum type for field validation

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

• by_value – whether to serialize by value or by symbol

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.Field(default=None, key=None, required=False, allow_none=True)

Bases: FieldABC

base class for serializable field

this is a class level descriptor for abstracting access to fields of serializable objects

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.Float(default=None, key=None, required=False, allow_none=True)

Bases: Field

serializable field for float data

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.Integer(default=None, key=None, required=False, allow_none=True)

Bases: Field

serializable field for integer data

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.List(default=None, key=None, field_type=None, required=False, allow_none=True)

Bases: Field

field type for list of serializable objects

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• field_type – specified type for list of nested objects

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.Nested(default=None, key=None, field_type=None, required=False, allow_none=True)

Bases: Field

field type for nested serializable object

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• field_type – specified type for nested object

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

class objectfactory.field.String(default=None, key=None, required=False, allow_none=True)

Bases: Field

serializable field for string data

Parameters:

• default – default value for field if unset

• key – dictionary key to use for field serialization

• required – whether this field is required to deserialize an object

• allow_none – whether null should be considered a valid value

marshmallow()

create generic marshmallow field to do actual serialization

Returns:

associated marshmallow field

objectfactory.serializable

serializable module

implements base class and metaclass for serializable objects

class objectfactory.serializable.Meta(name, bases, attributes, schema=None)

Bases: ABCMeta

metaclass for serializable classes

this is a metaclass to be used for collecting relevant field information when defining a new serializable class

define a new serializable object class, collect and register all field descriptors, construct marshmallow schema

Parameters:

• name – class name

• bases – list of base classes to inherit from

• attributes – dictionary of class attributes

• schema – (optional) predefined marshmallow schema

Returns:

newly defined class

class objectfactory.serializable.Serializable

Bases: SerializableABC

base class for serializable objects

deserialize(body: dict)

deserialize model from dictionary

Parameters:

body – serialized data to load into object

classmethod from_dict(body: dict)

constructor to set data with dictionary

Parameters:

body – dictionary

Returns:

new instance of serializable object

classmethod from_kwargs(**kwargs)

constructor to set field data by keyword args

Parameters:

kwargs – keyword arguments by field

Returns:

new instance of serializable object

serialize(include_type: bool = True, use_full_type: bool = True) → dict

serialize model to dictionary

Parameters:

• include_type – if true, type information will be included in body

• use_full_type – if true, the fully qualified path with be specified in body

Returns:

serialized object as dict