from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Model(BaseModel):
    pass


class Model2(BaseModel):
    a: Model


class Model3(BaseModel):
    c: Model
    d: Model2


@app.get("/", response_model=Model3)
def f():
    return {"c": {}, "d": {"a": {}}}


client = TestClient(app)


def test_get_api_route():

{* ../../docs_src/body_multiple_params/tutorial002_py310.py hl[20] *}


In this case, **FastAPI** will notice that there is more than one body parameter in the function (there are two parameters that are Pydantic models).

So, it will then use the parameter names as keys (field names) in the body, and expect a body like:

```JSON
{
    "item": {
        "name": "Foo",
        "description": "The pretender",

{* ../../docs_src/body_multiple_params/tutorial002_py310.py hl[20] *}

In diesem Fall wird **FastAPI** bemerken, dass es mehr als einen Body-Parameter in der Funktion gibt (zwei Parameter, die Pydantic-Modelle sind).

Es wird deshalb die Parameternamen als Schlüssel (Feldnamen) im Body verwenden und erwartet einen Body wie folgt:

```JSON
{
    "item": {
        "name": "Foo",

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip | Consejo

El parámetro de query `callback_url` utiliza un tipo <a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a> de Pydantic.

///

Lo único nuevo es `callbacks=invoices_callback_router.routes` como un argumento para el *decorador de path operation*. Veremos qué es eso a continuación.

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class BaseItem(BaseModel):
    description: str
    type: str


class CarItem(BaseItem):
    type: str = "car"


class PlaneItem(BaseItem):
    type: str = "plane"
    size: int


items = {
    "item1": {"description": "All my friends drive a low rider", "type": "car"},
    "item2": {

from fastapi import FastAPI, Form
from pydantic import BaseModel

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str
    model_config = {"extra": "forbid"}


@app.post("/login/")
async def login(data: FormData = Form()):

## Зависимости { #requirements }

Протестировав несколько вариантов, я решил, что в качестве основы буду использовать <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">**Pydantic**</a> и его преимущества.

from typing import Any

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from pydantic import BaseModel, ConfigDict, Field


@pytest.fixture(name="client")
def get_client():
    app = FastAPI()

    class ModelWithRef(BaseModel):
        ref: str = Field(validation_alias="$ref", serialization_alias="$ref")

from typing import Optional

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: Optional[float] = None
    owner_ids: Optional[list[int]] = None


@app.get("/items/valid", response_model=Item)
def get_valid():
    return {"name": "valid", "price": 1.0}


@app.get("/items/coerce", response_model=Item)

from typing import Union

from fastapi import FastAPI
from fastapi.responses import FileResponse
from pydantic import BaseModel


class Item(BaseModel):
    id: str
    value: str


responses = {
    404: {"description": "Item not found"},
    302: {"description": "The item was moved"},
    403: {"description": "Not enough privileges"},
}


app = FastAPI()


@app.get(
    "/items/{item_id}",