from typing import Union

from fastapi import FastAPI, Path
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int = Path(title="The ID of the item to get", ge=0, le=1000),
    q: Union[str, None] = None,

    }

    @Override
    public void artifactDownloading(RepositoryEvent event) {
        println("artifactDownloading", event.getArtifact() + " from " + event.getRepository());
    }

    @Override
    public void artifactDownloaded(RepositoryEvent event) {
        println("artifactDownloaded", event.getArtifact() + " from " + event.getRepository());
    }

/// note | Technical Details

You could also use `from starlette.responses import HTMLResponse`.

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

///

### `Response` { #response }

The main `Response` class, all the other responses inherit from it.

You can return it directly.

    // implementation.
    int from = 0;
    int to = 0;

    for (; from < list.size(); from++) {
      T element = list.get(from);
      if (!predicate.apply(element)) {
        if (from > to) {
          try {
            list.set(to, element);
          } catch (UnsupportedOperationException e) {
            slowRemoveIfForRemainingElements(list, predicate, to, from);
            return true;

from typing import Annotated, Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,

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

app = FastAPI()


class JsonApiResponse(JSONResponse):
    media_type = "application/vnd.api+json"


class Error(BaseModel):
    status: str
    title: str


class JsonApiError(BaseModel):
    errors: list[Error]


@app.get(
    "/a",
    status_code=204,

from typing import Optional

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

app = FastAPI()


class SubModel(BaseModel):
    a: Optional[str] = "foo"


class Model(BaseModel):
    x: Optional[int] = None
    sub: SubModel


class ModelSubclass(Model):
    y: int
    z: int = 0
    w: Optional[int] = None


class ModelDefaults(BaseModel):

import pytest
from fastapi import Depends, FastAPI, HTTPException
from fastapi.exceptions import RequestValidationError
from fastapi.testclient import TestClient
from starlette.responses import JSONResponse


def http_exception_handler(request, exception):
    return JSONResponse({"exception": "http-exception"})


def request_validation_exception_handler(request, exception):
    return JSONResponse({"exception": "request-validation"})

import importlib
import warnings

import pytest
from dirty_equals import IsInt
from fastapi.testclient import TestClient
from inline_snapshot import snapshot
from sqlalchemy import StaticPool
from sqlmodel import SQLModel, create_engine
from sqlmodel.main import default_registry

from tests.utils import needs_py310


def clear_sqlmodel():
    # Clear the tables in the metadata for the default base model
    SQLModel.metadata.clear()

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded`.