Uploading images in FastAPI post request causes 400 Bad Request

Question

I would like to get image via post request and then read it. I'm trying to do is this way:

import numpy as np
from PIL import Image
from fastapi import FastAPI, File, UploadFile, HTTPException, Depends
app = FastAPI()
@app.post("/predict_image")
    @logger.catch
    def predict_image(predict_image: UploadFile = File(...)):
        logger.info('predict_image POST request performed')
        try:
            pil_image = np.array(Image.open(predict_image.file))
        except:
            raise HTTPException(
                status_code=HTTP_422_UNPROCESSABLE_ENTITY, detail="Unable to process file"
            )
        pred = pil_image.shape
        logger.info('predict_image POST request performed, shape {}'.format(pred))
    return {'input_shape': pred}

Calling post request returns INFO: 127.0.0.1:59364 - "POST /predict_image HTTP/1.1" 400 Bad Request

How to fix it?

UPD:

Example from official tutorial return same exception:

@app.post("/uploadfile/")
async def create_upload_file(file: UploadFile = File(...)):
    return {"filename": file.filename}

Answer 1

You probably need to install python-multipart.

Just:

pip install python-multipart

Answer 2

Fixed this way:

@app.post("/predict_image/")
@logger.catch
def make_inference(file: bytes = File(...)):
    try:
        pil_image = np.array(Image.open(BytesIO(file)))

    except:
        raise HTTPException(
            status_code=HTTP_422_UNPROCESSABLE_ENTITY, detail="Unable to process file"
        )