FastAPI return image as JSON

Question

I have an API for random tea photos but would like it to return the photo in JSON as a URL for discord bots and things. This is what I have so far:

def getRandomFile(path):
  """
  Returns a random filename, chosen among the files of the given path.
  """
  files = os.listdir(path)
  index = random.randrange(0, len(files))
  return files[index]



@app.get("/")
async def home():
  return RedirectResponse("/docs")

@app.get("/tea")
def tea():
    x = "teacuppics/{}".format(getRandomFile("teacuppics"))
    return FileResponse(x)

How do I swap the reply of images to JSON reply?

Answer 1

You could use a static files directory to serve static files such as images. Include your teacuppics folder inside the static directory and mount a StaticFiles() instance in that directory. You can then use request.url_for() function to get the URL of a randomly selected image. Example below:

from fastapi.staticfiles import StaticFiles
from fastapi import FastAPI, Request

app = FastAPI()

app.mount("/static", StaticFiles(directory="static"), name="static")
  
@app.get('/tea')
def tea(request: Request):
    img = "teacuppics/{}".format(getRandomFile("static/teacuppics"))
    img_url = request.url_for('static', path=img)
    return {'img_url': img_url}

Answer 2

You can use request.url_for what generate url according to host. (on localhost it will be 127.0.0.1, on hosting it will be www.your-page.com). Argument is name of function. It was solved here as well.

from fastapi import FastAPI, Request
from fastapi.responses import FileResponse
from fastapi.responses import JSONResponse


app = FastAPI(title='FASTAPI BLANK', version='1')


@app.get("/tea/{img}")
async def tea(img: str) -> FileResponse:
    return FileResponse(img)


@app.get('/json_tea')
async def tea2(request: Request) -> JSONResponse:
    rnd_pic = '11dfdvf.jpg'
    pic_url = request.url_for('tea', img=rnd_pic)
    return JSONResponse(content={'teacuppics': pic_url})