Debug FastAPI application in VSCode

Question

i'm trying to debug an application (a web api) that use FastAPI (uvicorn) I'm also using poetry and set the projev virtual environment in vscode.

i read this tutorial to setup uvicorn and this one to setup vscode but i think i'm doing something wrong in set it up.

I tried to setup the launch.json both as python: module and python: current file

The problem seems that it doesn't recognize the project structure cause when i run the debug it stopped in an import statement with this error:

Exception has occurred: ImportError
attempted relative import with no known parent package

This is my current launch.json configuration:

"configurations": [
    {
        "name": "Python: local debug",
        "type": "python",
        "request": "launch",
        "program": "${workspaceFolder}/src/topic_service/service/__init__.py",
        "args" : ["--port", "8000"]
    },
]

I also tried to add a .env file setting PYTHONPATH:

PYTHONPATH=.:${PYTHONPATH}

Locally i run the application as follow:

poetry run uvicorn src.main:app --port 8080 --reload

Does anyone know how to correctly setup vscode to debug an uvicorn application?

Thank you

UPDATE: I also tried what this article says. the debugger seems to start but nothing happen (no breakpoint is triggered)

Answer 1

Try this configuration.

{
    "name": "Python: Module",
    "type": "python",
    "request": "launch",
    "module": "uvicorn",
    "args": ["src.main:app","--reload"]
}

Answer 2

The quick and easy way: launch debugger F5 and then select FastAPI Debug Configuration: (p.s. this works on the VSCode Insiders; haven't tried it on a regular version)