Flask can't find app file

There seems to a bug according to this github issue:

https://github.com/pallets/flask/issues/1829

As a workaround you can do

>python -m flask run

You can also use >python -m flask initdb later in the tutorial, when initializing the database (step 4).

You can give full path to app.py when you run "python app.py"

python C:/path/to/file/app.py