Default --app-dir makes __file__ ugly

[mila]

I use a slightly modified quickstart example to output value of the __file__ variable.

async def app(scope, receive, send):
    print(__file__)
    assert scope['type'] == 'http'
    await send({
        'type': 'http.response.start',
        'status': 200,
        'headers': [
            [b'content-type', b'text/plain'],
        ],
    })
    await send({
        'type': 'http.response.body',
        'body': __file__.encode(),
    })

When I run the app using uvicorn example:app, I get a path like /Users/mpojman/Projects/uvicorn-sandbox/./example.py. Note the unnecessary dot. This is caused by --app-dir, which defaults to ".".

I think that an empty string could be a better default value for this option. When I run the app using uvicorn example:app --app-dir "", __file__ is /Users/mpojman/Projects/uvicorn-sandbox/example.py as it should be.

The empty string would be consistent with Python behavior:

$ python -c 'import sys; print(repr(sys.path[0]))'
''

[Kludex]

If the behavior is the same, and you can point me out the discussion we had when it was introduced on a PR, I can review it.

[mila]

Thank you @Kludex.

• Pull requests is here: Change default --app-dir from from "." (dot) to "" (empty string). #1835
• --app-dir was added in Add --app-dir option for running uvicorn from any location #619. It seems to me that the dot was a natural choice for the current directory, so the empty string did not even come to mind.