Getting Attempted relative import in non-package error in spite of having __init__.py

Question

I have a package cclogger. This directory has a __init__.py file with some code to load the configuration. When I try to run the file api_main.py in that directory using the following command...

python -m cclogger.api_main

I get the following erro:-

config loaded
Instantiating DB with: cclogger/test123@localhost:x
Instantiated ParseCentral
Register parser called by : CitiIndia
Registered parser for email:  [email protected]
Instantiated SmsParseCentral
Register parser called by : Citi Bank
Registered sms parser for address:  lm-citibk
Register parser called by : HDFC Bank
Registered sms parser for address:  am-hdfcbk
Traceback (most recent call last):
  File "/Users/applegrew/Dropbox/Credit Expense/cclogger/cclogger/api_main.py", line 4, in <module>
    from .bottle import run, default_app, debug, get
ValueError: Attempted relative import in non-package

The messages displayed above the error are from modules in the same package which were imported by __init__.py.

The code in api_main.py is:-

import re
import os

from .bottle import run, default_app, debug, get
from .common_util import date_str_to_datetime, UTCOffset, date_filter

#app = Bottle()

default_app().router.add_filter('date', date_filter)

from . import api, dev

@get('/index')
def index():
    return "CCLogger API main live and kicking."

if dev:
    debug(True)
    run(reloader=True, port=9000)
else:
    os.chdir(os.path.dirname(__file__))
    application = default_app()

I have python 2.7.1.

What am I doing wrong? You can see the full code at https://github.com/applegrew/cclogger/tree/master/cclogger

Answer 1

You cannot run a python module directly as a script (I don't really know the reason why).

EDIT : The reason is explained in the PEP338 which is the spec for the "-m" option.

The release of 2.5b1 showed a surprising (although obvious in retrospect) interaction between this PEP and PEP 328 - explicit relative imports don't work from a main module. This is due to the fact that relative imports rely on __name__ to determine the current module's position in the package hierarchy. In a main module, the value of __name__ is always __main__ , so explicit relative imports will always fail (as they only work for a module inside a package).

For the 2.5 release, the recommendation is to always use absolute imports in any module that is intended to be used as a main module

To test your application, encapsulate api_main in a function and create a top-level main.py file which will run the main loop :

cclogger/api_main.py :

import re
import os


from .bottle import run, default_app, debug, get
from .common_util import date_str_to_datetime, UTCOffset, date_filter

#app = Bottle()


def main():
    default_app().router.add_filter('date', date_filter)

    from . import api, dev

    @get('/index')
    def index():
        return "CCLogger API main live and kicking."

    if dev:
        debug(True)
        run(reloader=True, port=9000)
    else:
        os.chdir(os.path.dirname(__file__))
        application = default_app()

And /main.py :

from cclogger import api_main


if __name__ == '__main__':
    api_main.main()

You can run your application by typing python main.py, python -m main or python -c "import cclogger.api_main; api_main.main()" .

PS : thanks for linking the complete source, it's always much more helpful than the stubs provided with the question.