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Address already in use – FastAPI

I keep getting [Errno 98] Address already in use But the address is not in use. I tried to change the ip and port but It isn’t budging.

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def main():
return {"message": "Helloworld，FastAPI"}


if __name__ == '__main__':
import uvicorn
uvicorn.run(app, host="127.0.0.1", port=8000)

uvicorn main:app --reload also tried uvicorn main:app --host=172.0.0.2 --port=5000 then it gives [Errno 99] error while attempting to bind on address ('172.0.0.2', 5000): cannot assign requested address I tried running a flask dev server and it was also running on 172.0.0.1 without a problem?

using Arch-Manjaro-Linux

I used nmap to see what the fuss was about.

But only 2 ports in use on the 127.0.0.1 IP

PORT     STATE SERVICE
631/tcp  open  ipp
8000/tcp open  http-alt

I would use another IP and port but it gives an error that it can’t be assigned.

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Answer

Basically, you can do this. This will kill the process that listens TCP connections on port 8000

sudo lsof -t -i tcp:8000 | xargs kill -9
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