Pydantic - Upgrading object to another model

Question

I have a NewUser model that is something that the end user inputs, I want to update the object to a UserInDB so that I can pass it to my db engine (DynamoDB, which expects a dict)

At the moment I'm calling .dict twice, which doesn't feel like the correct way to do it

    from pydantic import BaseModel, Field
    from datetime import datetime
    from typing import Optional
    from uuid import uuid4
    
    class NewUser(BaseModel):
        name: str
        email: str
        company_name: Optional[str]
    
    class UserInDB(NewUser):
      hash: str = Field(default_factory= lambda: uuid4())
      range = 'DATA'
      created_at: datetime = Field(default_factory= lambda: datetime.now())
    
    #...
    #Emulating what an end user would send
    user = NewUser(name='Example', company_name='example', email='example@example.com')
    
    #Is calling dict twice way to do it?
    user_in_db = UserInDB(**user.dict()).dict()
    db.create_user(user_in_db)

IMHO, there is nothing wrong in calling the `.dict()` twice, you really need that. — JPG, Oct 20 '20 at 14:39

score 2 · Answer 1 · answered Nov 19 '22 at 22:05

You could try to define an __init__ and the code would look nicer (to me at least).

from pydantic import BaseModel, Field
from datetime import datetime
from typing import Optional
from uuid import uuid4

class NewUser(BaseModel):
    name: str
    email: str
    company_name: Optional[str]

class UserInDB(NewUser):
    hash: str = Field(default_factory= lambda: uuid4())
    range = 'DATA'
    created_at: datetime = Field(default_factory= lambda: datetime.now())

    def __init__(self, user: NewUser):
        super().__init__(**user.dict())

#...
# Emulating what an end user would send
user = NewUser(name='Example', company_name='example', email='example@example.com')

# This looks probably better
user_in_db = UserInDB(user)

Pydantic - Upgrading object to another model

1 Answers1