dantico 0.0.5

Tools to convert Django ORM models to Pydantic models

dantico

Tools to convert Django ORM models to Pydantic models.

The key features are:

• Custom Field Support: Create Pydantic Schemas from Django Models with default field type validations out of the box.

• Field Validator: Fields can be validated with model_validator just like Pydantic validator or root_validator.

Requirements

• Python 3.6+
• Django 2.2+
• Pydantic 1.6+

Installation

pip install dantico

Usage

Here are a few examples of what you can do with Dantico:

Field Validator

model_validator(*args, **kwargs) is a substitute for Pydantic validator used for pre and post fields validation. Their functionalities are the same. More information can be found here.

from django.contrib.auth import get_user_model
from dantico import ModelSchema, model_validator

UserModel = get_user_model()


class CreateUserSchema(ModelSchema):
    class Config:
        model = UserModel
        # Fields to include, by default include all the fields
        # from the Django model
        include = ["username", "email", "password"]

    @model_validator("username")
    def validate_unique_username(cls, value_data: str) -> str:
        if UserModel.objects.filter(username__icontains=value_data).exists():
            raise ValueError("Username exists")
        return value_data

Generate schema instance

You can generate a schema instance from your django model instance using from_orm(cls, obj: Any)

from typings import Optional
from django.contrib.auth import get_user_model
from dantico import ModelSchema, model_validator

UserModel = get_user_model()

new_user = UserModel.objects.create_user(
    username="Max",
    email="[e-mail]",
    password="password",
    first_name="Max",
    last_name="Shapira",
)


class UserSchema(ModelSchema):
    class Config:
        model = UserModel
        # Include all the fields from a model except 'password' field
        exclude = ["password"]

schema = UserSchema.from_orm(new_user)

print(schema.json(indent=2)
{
    "id": 1,
    "first_name": "Max",
    "last_name": "Shapira",
    "email": "[e-mail]",
    "username": "Max",
}

From ModelSchema to Django Model

You can transfer data from your ModelSchema to Django Model instance using apply(self, model_instance, **kwargs). The apply function uses Pydantic model .dict function, dict function filtering what can be passed as kwargs to the .apply function.

For more information, check out Pydantic model export.

from typings import Optional
from django.contrib.auth import get_user_model
from dantico import ModelSchema, model_validator

UserModel = get_user_model()

new_user = UserModel.objects.create_user(
      username="Max",
      email="[e-mail]",
      password="password",
  )


class UpdateUserSchema(ModelSchema):
    class Config:
        model = UserModel
        include = ["first_name", "last_name", "username"]
        optional = ["username"]  # 'username' is now optional

schema = UpdateUserSchema(first_name="Max", last_name="Shapira")
schema.apply(new_user, exclude_none=True)

assert new_user.first_name == "Max" # True
assert new_user.username == "Max" # True

License

This project is licensed under the terms of the MIT license.