En-têtes, cookies et réponses personnalisées

Beyond the JSON Body

Reading a Header

from fastapi import FastAPI, Header

app = FastAPI()

@app.get('/info')
async def info(user_agent: str = Header(default=None)):
    return {'ua': user_agent}

Reading Cookies

from fastapi import Cookie

@app.get('/session')
async def session(session_id: str = Cookie(default=None)):
    return {'session': session_id}

Setting Headers on a Response

from fastapi import Response

@app.get('/items')
async def items(response: Response):
    response.headers['X-Total-Count'] = '42'
    return ['a', 'b']

Setting Cookies

@app.post('/login')
async def login(response: Response):
    response.set_cookie('session_id', 'abc123', httponly=True, secure=True)
    return {'ok': True}

Plain Text and HTML Responses

from fastapi.responses import PlainTextResponse, HTMLResponse

@app.get('/text', response_class=PlainTextResponse)
async def text():
    return 'hello'

@app.get('/page', response_class=HTMLResponse)
async def page():
    return '<h1>Hi</h1>'

Redirects

from fastapi.responses import RedirectResponse

@app.get('/old')
async def old():
    return RedirectResponse(url='/new', status_code=301)

Header Name Conversion

def to_header_name(param):
    return '-'.join(w.capitalize() for w in param.split('_'))
print(to_header_name('user_agent'))
print(to_header_name('x_api_key'))

Streaming Responses

from fastapi.responses import StreamingResponse

def rows():
    for i in range(3):
        yield f'row {i}\n'

@app.get('/export')
async def export():
    return StreamingResponse(rows(), media_type='text/plain')

Custom Status Codes

from fastapi import status

@app.post('/items', status_code=status.HTTP_201_CREATED)
async def create():
    return {'created': True}

Security Notes

Quick Check

Recap