pydictable

A pure python, zero dependency solution for

1. Schema (json/dict) validation
2. Serialize/Deserialize to json

Installation

pip install pydictable

Example

class LatLng(DictAble):
    lat: int
    lng: int

class Address(DictAble):
    pin_code: int
    lat_lng: LatLng

class Person(DictAble):
    name: str
    address: Address

input_dict = {
    'name': 'Pramod',
    'address': {
        'pin_code': 560032,
        'lat_lng': {
            'lat': 12345,
            'lng': 67890
        }
    }
}

p = Person(dict=input_dict) # Raises DataValidationError if not valid
p.name # Pramod
p.address # Address object
p.address.pin_code # 560032

p.to_dict() == input_dict # Serialize

p.address.pin_code = 518466 # You can change the values

# you can initiate with named params too
p2 = Person(
    name='Pramod',
    address=Address(
        pin_code=560032,
        lat_lng=LatLng(
            lat=12345,
            lng=67890
        )
    )
)

Person.get_input_schema() # Get the Schema spec as json!

Extendability

You can quickly build your own fields as explained below

class PositiveIntField(IntField):
    def validate_json(self, field_name: str, v):
        assert v > 0, 'Should be positive integer'

class Person(DictAble):
    age: int = PositiveIntField()

Person(dict={'age': -1}) # Raises DataValidationError

Polymorphism

Auto converts multiple types

class Homo(DictAble):
    name: str

class Neanderthal(Homo):
    animals_killed: int

class Sapien(Homo):
    words_spoken: int

class Human(DictAble):
    species: Homo = MultiTypeField([Neanderthal, Sapien])

human = Human(dict={
    'species': {
        'name': 'Mufasa',
        'words_spoken': 1024,
        '__type': 'Sapien'
    }
})
assert human.species.name == 'Mufasa'
assert isinstance(human.species, Sapien)
assert human.species.words_spoken == 1024

Feel free to report bugs or push changes! Cheers!