aio-libs/aiohttp · error · HTTPMethodNotAllowed

Method Not Allowed

Error message

Method Not Allowed

What it means

Error "Method Not Allowed" thrown in aio-libs/aiohttp.

Source

Thrown at aiohttp/web_urldispatcher.py:933

class View(AbstractView):
    async def _iter(self) -> StreamResponse:
        if self.request.method not in hdrs.METH_ALL:
            self._raise_allowed_methods()
        method: Callable[[], Awaitable[StreamResponse]] | None = getattr(
            self, self.request.method.lower(), None
        )
        if method is None:
            self._raise_allowed_methods()
        return await method()

    def __await__(self) -> Generator[None, None, StreamResponse]:
        return self._iter().__await__()

    def _raise_allowed_methods(self) -> NoReturn:
        allowed_methods = {m for m in hdrs.METH_ALL if hasattr(self, m.lower())}
        raise HTTPMethodNotAllowed(self.request.method, allowed_methods)


class ResourcesView(Sized, Iterable[AbstractResource], Container[AbstractResource]):
    def __init__(self, resources: list[AbstractResource]) -> None:
        self._resources = resources

    def __len__(self) -> int:
        return len(self._resources)

    def __iter__(self) -> Iterator[AbstractResource]:
        yield from self._resources

    def __contains__(self, resource: object) -> bool:
        return resource in self._resources


class RoutesView(Sized, Iterable[AbstractRoute], Container[AbstractRoute]):
    def __init__(self, resources: list[AbstractResource]):

View on GitHub (pinned to c0ef574e29)

When it happens

Trigger: Thrown at aiohttp/web_urldispatcher.py:933 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of aio-libs/aiohttp@c0ef574e29 (2026-08-04). Data as JSON: /data/errors/5740f71830dd3cf6.json. Report an issue: GitHub.