bfh

BFH: a library for mapping schemas to other schemas.

class bfh.Schema(*args, **kwargs)

A base class for defining your schemas:

Declare the shape of an object you expect to handle.

Just inherit this and add some fields:

class Animal(Schema):
    name = UnicodeField()
    type = UnicodeField()
    legs = IntegerField()
    noise = UnicodeField()

serialize(implicit_nulls=False)

Represent this schema as a dictionary.

Handy for dumping to json or some other further serialization format, or splatting into an object constructor.

Parameters:implicit_nulls (bool) – drop any keys whose value is nullish Returns:dict

validate()

Validate the values in the schema.

Returns:True Raises:Invalid

class bfh.Mapping

A base class for defining your mappings:

Declare a transformation from one shape to another shape.

Just inherit this and add some fields:

class DogToAnimal(Mapping):
    source_schema = Dog
    target_schema = Animal

    name = Get('dogname')
    type = Const('dog')
    legs = Const(4)
    noise = Const('woof!')

The action happens when you get an instance of your mapping:

dog_to_animal_map = DogToAnimal()

Then apply it to an object. You get a Schema instance:

my_animal = dog_to_animal_map.apply(my_dog)
type(my_animal)
# __main__.Animal

... which is full of values:

my_animal.serialize()
# {"name": "Fido", "type": "dog", "legs": 4, "noise": "woof!}

apply(blob)

Take the mapping and push a blob through it.

Parameters:blob (dict or Schema) – the thing to transform Returns:instance of self.target_schema (if declared) or GenericSchema