[Python] Read a body JSON list with FastAPI

The body of an HTTP PUT request is a JSON list - like this:

[item1, item2, item3, ...]


I can't change this. (If the root was a JSON object rather than a list there would be no problem.)

Using FastAPI I seem to be unable to access this content in the normal way:

@router.put('/data')
def set_data(data: DataModel): # This doesn't work; how do I even declare DataModel?


I found the following workaround, which seems like a very ugly hack:

class DataModel(BaseModel):
__root__: List[str]


from fastAPI import Request

@router.put('/data')
async def set_data(request: Request): # Get the request object directly
data = DataModel(__root__=await request.json())


This surely can't be the 'approved' way to achieve this. I've scoured the documentation both of FastAPI and pydantic. What am I missing?

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