Ahora, obtén los datos del usuario desde la base de datos (falsa), usando el `username` del campo del form.

Si no existe tal usuario, devolvemos un error diciendo "Incorrect username or password".

Para el error, usamos la excepción `HTTPException`:

{* ../../docs_src/security/tutorial003_an_py310.py hl[3,79:81] *}

### Revisa el password { #check-the-password }

var keyInPolicyExceptions = map[string]bool{
	xhttp.AmzSignature: true,
	"File":             true,
	"Policy":           true,

	// MinIO specific exceptions to the general S3 rule above.
	encrypt.SseKmsKeyID:          true,
	encrypt.SseEncryptionContext: true,
	encrypt.SseCustomerAlgorithm: true,
	encrypt.SseCustomerKey:       true,
	encrypt.SseCustomerKeyMD5:    true,

from typing import Union

import pytest
from fastapi import Body, Cookie, FastAPI, Header, Path, Query
from fastapi.exceptions import FastAPIDeprecationWarning
from fastapi.testclient import TestClient
from pydantic import BaseModel, ConfigDict


def create_app():
    app = FastAPI()

    class Item(BaseModel):
        data: str

        model_config = ConfigDict(

### Multi destination replication

The replication design for multiple sites works in a similar manner as described above for two site scenario. However there are some
important exceptions.

Replication status on the source cluster will be marked as `COMPLETED` only after replication is completed on all targets. If one or more targets failed replication, the replication status is reflected as `PENDING`.

                      &FloatDeallocator, nullptr);
}

// All the *Helper methods are used as a workaround for the restrictions that
// one cannot call ASSERT_* methods in non-void-returning functions (when
// exceptions are disabled during compilation)
void PlaceholderHelper(TF_Graph* graph, TF_Status* s, const char* name,
                       TF_DataType dtype, const std::vector<int64_t>& dims,
                       TF_Operation** op) {

import warnings
from collections.abc import Sequence
from dataclasses import dataclass
from enum import Enum
from typing import Annotated, Any, Callable, Optional, Union

from fastapi.exceptions import FastAPIDeprecationWarning
from fastapi.openapi.models import Example
from pydantic import AliasChoices, AliasPath
from pydantic.fields import FieldInfo
from typing_extensions import Literal, deprecated

from ._compat import (
    Undefined,
)

from typing import Annotated, Any, Optional, Union, cast

from annotated_doc import Doc
from fastapi.exceptions import HTTPException
from fastapi.openapi.models import OAuth2 as OAuth2Model
from fastapi.openapi.models import OAuthFlows as OAuthFlowsModel
from fastapi.param_functions import Form
from fastapi.security.base import SecurityBase
from fastapi.security.utils import get_authorization_scheme_param
from starlette.requests import Request

// used to e.g. quickly compare objects or check whether
// the content of an object has changed.
//
// In general, an S3 ETag is an MD5 checksum of the object
// content. However, there are many exceptions to this rule.
//
// # Single-part Upload
//
// In case of a basic single-part PUT operation - without server
// side encryption or object compression - the ETag of an object
// is its content MD5.
//

from typing import Union

import pytest
from fastapi import FastAPI
from fastapi.exceptions import FastAPIError, ResponseValidationError
from fastapi.responses import JSONResponse, Response
from fastapi.testclient import TestClient
from pydantic import BaseModel


class BaseUser(BaseModel):
    name: str


class User(BaseUser):
    surname: str


class DBUser(User):
    password_hash: str


class Item(BaseModel):

### Acerca de `root_path` { #about-root-path }

Ten en cuenta que el servidor (Uvicorn) no usará ese `root_path` para nada, a excepción de pasárselo a la app.

Pero si vas con tu navegador a <a href="http://127.0.0.1:8000/app" class="external-link" target="_blank">http://127.0.0.1:8000/app</a> verás el response normal:

```JSON
{