Flask fails to start with use_reloader=True when using absolute import

I’m using Flask v0.10.1 and I have the following project structure:

test
├── api
│   ├── hello.py
│   └── __init__.py
├── config
│   ├── config.py
│   └── __init__.py
└── __init__.py

The hello.py file is:

import sys
import flask
from test.config import config

app = flask.Flask(__name__)

@app.route('/hello')
def hello():
    return config.MESSAGE

def main(argv):
    reloader = '--reloader' in argv
    print('Starting with reloader={}'.format(reloader))
    app.run(host='0.0.0.0', port=8080, debug=True, use_reloader=reloader)

if __name__ == '__main__':
    main(sys.argv)

and the config.py is simply

MESSAGE = 'Hello!'

When I run api.py with use_reloader=False (python -m test.api.hello) the server starts correctly. If I run it with use_reloader=True (python -m test.api.hello --reloader) it fails with:

Starting with reloader=True
 * Running on http://0.0.0.0:8080/
 * Restarting with reloader
Traceback (most recent call last):
  File "/home/kostas/Tmp/testproj/test/api/hello.py", line 3, in <module>
    from test.config import config
ImportError: No module named config

[bootc]

I personally fixed this using the following in my equivalent of hello.py:

# Workaround for the werkzeug reloader removing the current directory from the
# path. It's nasty, but it works! Inspired by:
# https://github.com/mitsuhiko/flask/issues/1246
os.environ['PYTHONPATH'] = os.getcwd()

Just do that before you call app.run() with the reloader enabled; that seems to fix it for me.

[untitaker]

The current solution is to avoid running your app via python -m ....

The issue I linked above contains all the details and why this is an unfixable problem AFAIK

On 18 June 2015 11:59:41 CEST, “Piotrek Szymański” [e-mail] wrote:

Same issue here, app fails to load absolute import when using debug=True. Debug=False works fine.

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Reply to this email directly or view it on GitHub: https://github.com/mitsuhiko/flask/issues/1246#issuecomment-113097027