If your application is **simple**, this will probably **not be a problem**, and you might not need to specify hard memory limits. But if you are **using a lot of memory** (for example with **machine learning** models), you should check how much memory you are consuming and adjust the **number of containers** that runs in **each machine** (and maybe add more machines to your cluster).

This kind of asynchronicity is what made NodeJS popular (even though NodeJS is not parallel) and that's the strength of Go as a programming language.

And that's the same level of performance you get with **FastAPI**.

        },
        "baz": "simple_include_dict model2 baz",
    }


@app.get(
    "/simple_exclude",
    response_model=Model2,
    response_model_exclude={"ref": {"bar"}},
)
def simple_exclude():
    return Model2(
        ref=Model1(foo="simple_exclude model foo", bar="simple_exclude model bar"),
        baz="simple_exclude model2 baz",
    )


@app.get(
    "/simple_exclude_dict",

    from pydantic import BaseModel, ValidationInfo, field_validator

    app = FastAPI()

    class ModelB(BaseModel):
        username: str

    class ModelC(ModelB):
        password: str

    class ModelA(BaseModel):
        name: str
        description: Optional[str] = None
        foo: ModelB

        @field_validator("name")
        def lower_username(cls, name: str, info: ValidationInfo):

 * string is not human readable, but can be used with classes like [InetAddress] to establish
 * connections.
 *
 * ## Why another URL model?
 *
 * Java includes both [java.net.URL][URL] and [java.net.URI][URI]. We offer a new URL
 * model to address problems that the others don't.
 *
 * ### Different URLs should be different
 *

    - [CVE-2023-3955: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3955-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
    - [CVE-2023-3676: Insufficient input sanitization on Windows nodes leads to privilege escalation](#cve-2023-3676-insufficient-input-sanitization-on-windows-nodes-leads-to-privilege-escalation)
  - [Changes by Kind](#changes-by-kind-14)

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():

    return client


@needs_pydanticv1
def test_filter_sub_model(client: TestClient):
    response = client.get("/model/modelA")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "name": "modelA",
        "description": "model-a-desc",
        "model_b": {"username": "test-user"},
    }


@needs_pydanticv1
def test_validator_is_cloned(client: TestClient):

{* ../../docs_src/body/tutorial001.py hl[4] *}

## Créez votre modèle de données

Déclarez ensuite votre modèle de données en tant que classe qui hérite de `BaseModel`.

Utilisez les types Python standard pour tous les attributs :

{* ../../docs_src/body/tutorial001.py hl[7:11] *}

        response_fields = {}
        for additional_status_code, response in self.responses.items():
            assert isinstance(response, dict), "An additional response must be a dict"
            model = response.get("model")
            if model:
                assert is_body_allowed_for_status_code(
                    additional_status_code
                ), f"Status code {additional_status_code} must not have a response body"