Flask - Importerror: No Module Named App
First I Created __Init__. Py from Flask Import Flask App = Flask(__Name__) Then in a Separate File, in the Same Directory, Run. Py from App Import App App...
First I created __init__.py
from flask import Flask
app = Flask(__name__)
Then in a separate file, in the same directory, run.py
from app import app
app.run(
debug = True
)
When I try to run run.py, I get the error
Traceback (most recent call last):
File "run.py", line 1, in <module>
from app import app
ImportError: No module named app
9 Answers
__init__.py is imported using a directory. if you want to import it as app you should put __init__.py file in directory named app
a better option is just to rename __init__.py to app.py
This is probably an error in flask application's folder structure.
Anyone looking for a simple beginner-friendly structure for the flask project may find this helpful:
|__movies
|__run.py
|__app
├── templates
│ └── index.html
│ └── signup.html
└── __init__.py
└── routes.py
Here 'movies' is the name given for the main application. It contains 'run.py' and a folder called 'app'. 'app' folder contains all necessary flask files such as 'templates' folder, '__init __.py', and 'routes.py'.
Contents of:
run.py:
from app import app
__init__.py:
from flask import Flask
app = Flask(__name__)
from app import routes
app.run(debug=True)
routes.py:
from app import app
@app.route('/')
@app.route('/index')
def index():
return "Hello, World!"
Your __init__.py file needs to go in the folder named app, not the same directory as the run.py file.
from app import app is looking in the app folder, so the __init__.py file needs to sit in there.
Ensure to set your PYTHONPATH to the src/ directory as well. Example
export PYTHONPATH="$PYTHONPATH:/path/to/your/src"
Just rename your file to app.py and it will works.
(In case someone else is lost even after trying other solutions..)
I get the No module named app error only when Debugging, not when Running.
That's because I had set debug=True in my app.py's __main__ (which kindly auto-reloads flask when we save code changes) :
app.run(debug=True)
But if you try to Debug in your IDE now, it gives above error.
Fix : set debug=False
app.run(debug=False)
and it works like a magic trick illusion.
For me, export PYTHONPATH=/path/to/your/src && python app/main.py works
I solved this as follows -
$export FLASK_APP=run
$flask run
After executing this command. I don't get any error, my app running smoothly.
This may be an isolated case, but for me this was a VS Code issue. The "no module found" error would only happen when debug=True.
In VS Code, you can "Run Python File" or "Debug Python File". I was using debug in VS Code AND I had app.run(debug=True). Once I just ran the file normally in VS Code, the problem went away and Flask debugger is working as expected.
I guess it doesn't like 2 layers of Inception!
Maya is a hardware enthusiast who tests and reviews smart home devices, smartphones, wearables, and audio gear. She focuses on practical consumer value and build quality.
