pydantic-model-parser 1.0.1

A simple package to transform/map dictionaries, before parsing it into Pydantic.

Pydantic Model Parser

A simple package to transform/map dictionaries, before parsing it into Pydantic.

Requirements

• The models/entities should conform to Pydantic's Model specifications and should inherit the pydantic.BaseModel.

Installation

pip3 install pydantic-model-parser

Usage

Firstly, define your entity using Pydantic's BaseModel.

# comment.py
from pydantic import BaseModel

class User(BaseModel):
    id: int
    name: str


class Comment(BaseModel):
    id: int
    comment_str: str
    user: User

Next, define the Mapper. The mapper can be used to rearrange dictionary keys and perform transformations on the values.

The tuples definitions are as follows:

• (old_field_path: str, new_field_path: str, transform_func: Optional[Callable])
• transform_func of None maps the value as per the original value
• transform_func of lambda x: x * 2 maps the value as double of the original value
• old_field_path's value is placed in new_field_path in the new dictionary and subsequently parsed into the BaseModel
  • The . in the path delimits the nested levels in the dictionaries. e.g. user.id refers to:

{
    "user": {
        "id": 1
    }
}

Defining a Mapper:

# comment.py
from model_parser.custom_types import Mapping
from model_parser.mapper import BaseMapper

class CommentMapper(BaseMapper):
    @staticmethod
    def get_mapping() -> List[Mapping]:
        return [
            ('id', 'id', None),
            ('comment_str', 'comment_str', None),
            ('user_name', 'user.name', None),
            ('user_id', 'user.id', None)
        ]

Lastly, to parse objects:

# main.py
from comment import Comment, CommentMapper

data = {
        "id": 1,
        "comment_str": "HelloWorld",
        "user_id": 2,
        "user_name": "bob"
    }
data_list = [data, data]
parser = Parser(Comment, CommentMapper)

# parse into a Comment entity
comment = parser.parse(data)

# parse into a list of Comment entities
comments = parser.parse(data_list)