[Python] Flask AttributeError: module 'app' has no attribute 'run'

My Flask project is structured as follows:

my_project
│
├── app
│ ├── __init__.py
│ ├── api
│ ├── static
│ └── templates
├── config.py
└── run.py


app/__init__.py:

from flask import Flask

app = Flask(__name__)

app.config.from_object('config')


run.py

from app import app

app.run(
host=app.config.get('HOST', '0.0.0.0'),
port=app.config.get('PORT', 5000)
)


This worked before, but I'm trying to migrate my project from Python 2 to Python 3, and running python run.py no longer works. I get the following error:

Traceback (most recent call last):
File "/Users/rasmi/Projects/my_project/run.py", line 3, in <module>
app.run(
AttributeError: module 'app' has no attribute 'run'


If I change the import style in run.py to match the one here:

from .app import app

app.run(
host=app.config.get('HOST', '0.0.0.0'),
port=app.config.get('PORT', 5000)
)


I get a different error:

Traceback (most recent call last):
File "/Users/rasmi/Projects/my_project/run.py", line 1, in <module>
from .app import app
ModuleNotFoundError: No module named '__main__.app'; '__main__' is not a package


Wrapping my app.run() call in an if __name__ == '__main__': block yields the same results. What's causing this issue?

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