implementing JSON Data Extraction Using FastAPI and Pydantic for Nested Dictionaries
This might be a silly question, but Could someone explain I'm working on a project and hit a roadblock..... Quick question that's been bugging me - I'm currently working with a question with extracting data from a nested JSON object using FastAPI and Pydantic models. I have the following JSON structure returned from a third-party API: ```json { "user": { "id": 1, "name": "John Doe", "address": { "street": "123 Main St", "city": "Anytown", "zip": "12345" } } } ``` I've defined my Pydantic models like this: ```python from pydantic import BaseModel class Address(BaseModel): street: str city: str zip: str class User(BaseModel): id: int name: str address: Address ``` When I attempt to extract the user data in my FastAPI endpoint, I have the following code: ```python from fastapi import FastAPI from fastapi.responses import JSONResponse app = FastAPI() @app.get("/user/{user_id}", response_model=User) async def get_user(user_id: int): # Simulated response from an external API call external_response = { "user": { "id": user_id, "name": "John Doe", "address": { "street": "123 Main St", "city": "Anytown", "zip": "12345" } } } return JSONResponse(content=external_response) ``` However, when I call the `/user/1` endpoint, I get the following behavior: ``` ValidationError: 1 validation behavior for User user field required (type=value_error.missing) ``` It seems that FastAPI expects the JSON to directly match the User model, but the response is nested under the "user" key. I tried modifying the response like this: ```python return JSONResponse(content=external_response['user']) ``` This works fine, but I'm concerned about maintaining code readability and structure, especially as the API grows. Is there a more elegant solution to handle extracting nested JSON while keeping the response model intact? Any best practices for dealing with such cases in FastAPI would be greatly appreciated! I'm working on a web app that needs to handle this. How would you solve this? For context: I'm using Python on Windows. Any ideas what could be causing this? For reference, this is a production CLI tool. I appreciate any insights! I've been using Python for about a year now.