Pydantic params validation with file upload

Question

I'm trying upload user data with file. I wanna do something like this, validate user data and attach file

class User(BaseModel):
    user: str
    name: str

@router.post("/upload")
async def create_upload_file(data: User, file: UploadFile = File(...)):
    print(data)
    return {"filename": file.filename}

but it doesn't work Error: Unprocessable Entity Response body:

{
  "detail": [
    {
      "loc": [
        "body",
        "data"
      ],
      "msg": "value is not a valid dict",
      "type": "type_error.dict"
    }
  ]
}

But if i do separate ulr all work:

class User(BaseModel):
    user: str
    name: str

@router.post("/d")
async def create(file: UploadFile = File(...)):
    return {"filename": file.filename}

@router.post("/")
def main(user: User):
    return user

How to combine all together?

Answer 1

You can't have them at the same time, since pydantic models validate json body but file uploads is sent in form-data .

So they can't be used together.

If you want to do it you should do a trick.

Please check out this link to know how to use pydantic models in form data.

Answer 2

You can't declare Body fields that you expect to receive as JSON, along with Form fields, as the request will have the body encoded using application/x-www-form-urlencoded , instead of application/json (or multipart/form-data , when files are included).

You can either use Form (...) fields, or Dependencies with Pydantic models, as described here .