🐛 Type annotations for headers in HTTPException declare Any as values but only accept str

[tiangolo]

🐛 Type annotations for headers in HTTPException declare Any as values but only accept str.

Fixed in #9648

Discussed in #8562

^{Originally posted by DorAbu January 20, 2022}

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Example Code

from fastapi import FastAPI, HTTPException

app = FastAPI()


@app.get("/")
async def root():
    raise HTTPException(
        status_code=503,
        detail=f"The server is not ready to handle the request, due to ...",
        headers={"Retry-After": 20}
    )

Description

In HTTPException object signature (attached below 1.), headers type hint is Optional[Dict[str, Any]].
But for example, when Dict[str, int] is given as in the "example code" section, the implementation in Starlette will raise an exception - AttributeError: 'int' object has no attribute 'encode' (attached below 2.).

Seems that Starlette implementation expects Optional[Dict[str, str]] type hint, FastAPI may resolve it by converting the values of the headers to strings.

1. 
2. 

Operating System

Windows

Operating System Details

No response

FastAPI Version

0.70.1

Python Version

3.8.9 (tags/v3.8.9:a743f81, Apr 6 2021, 14:02:34) [MSC v.1928 64 bit (AMD64)]

Additional Context

starlette==0.16.0

[tiangolo]

Fixed in #9648