settings.py文件中的Django AttributeError

Question

I've been stuck all day on what seems to be a very silly import problem. From my Django project directory, I can import a module and run a function just fime:

(msg-gw)slashingweapon:~/msg-gw/www$ python 
>>> import snpp
>>> snpp.config_url('snpp://server.name.com:1234?user=me&pass=whatever')
{'host': 'server.name.com', 'pass': 'whatever', 'port': 1234, 'user': 'me'}

But when I try to run my app, either through manage.py or by gunicorn , I get an attribute error:

(msg-gw)slashingweapon:~/msg-gw/www$ python manage.py runserver 8000
  File "/home/slashingweapon/msg-gw/www/project/settings.py", line 26, in <module>
    SNPP = snpp.config_url('snpp://server.name.com:1234?user=me&pass=whatever')
AttributeError: 'module' object has no attribute 'config_url'

The two relevant lines in my settings.py file are exactly what you would expect. Notice that I can import the module just fine, but the config_url() function isn't found.

import snpp
SNPP = snpp.config_url('snpp://server.name.com:1234?user=me&pass=whatever')

The directory layout is exactly what you would expect:

www
  |
  +-project
  |   +-__init__.py
  |   +-settings.py
  |   +-urls.py
  |   +-views.py
  |   +-wsgi.py
  |
  +-snpp
      +-__init__.py
      +-protocol.py
      +-views.py
      +-urls.py

The config_url() function is defined inside snpp/__init__.py

I have tried all kinds of things:

• from snpp import config_url
• move config_url to the file snpp/config and then import with
  • import snpp.confg
  • from snpp.config import config_url
  • from snpp import config and then invoke through config.config_url()

The __init__.py file is nothing special. It just lets you encode some server information as a string, so you can stick your SNPP config into the environment:

import urlparse

def config_url(urlStr):

    config = {
        'host':None,
        'port':444,
        'user':None,
        'pass':None,
    }

    url = urlparse.urlparse(urlStr)
    if url.scheme == 'snpp':
        locParts = url.netloc.split(":")
        config['host'] = locParts[0]
        if len(locParts) > 1:
            port = int(locParts[1])
            if port > 0:
                config['port'] = port

        args = urlparse.parse_qs(url.query)
        config['user'] = args.get('user', [None])[0]
        config['pass'] = args.get('pass', [None])[0]

    return config

I am using Python 2.7, django 1.5.1, and virtualenv.

Other parts of my project work well. When I print out the path in my browser, it looks correct. Importing snpp should not be a problem, since snpp is in the www directory:

• /home/slashingweapon/msg-gw/www
• /home/slashingweapon/msg-gw/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg
• /home/slashingweapon/msg-gw/lib/python2.7/site-packages/pip-1.3.1-py2.7.egg
• /home/slashingweapon/msg-gw/lib/python2.7/site-packages/django_json_rpc-0.6.2-py2.7.egg
• /home/slashingweapon/msg-gw/lib/python27.zip
• /home/slashingweapon/msg-gw/lib/python2.7
• ... etc ...

It doesn't matter if the snpp module is in my INSTALLED_APPS list or not. I get the same result.

Solved

With the help of SO denizens, I found the problem.

I had refactored my application by moving some reusable code pieces from the project directory to the new snpp directory. When I did that, I neglected to move or delete the *.pyc files.

The value of snpp.__file__ was:

/home/slashingweapon/msg-gw/www/project/snpp.pyc

instead of the expected:

/home/slashingweapon/msg-gw/www/snpp/__init__.pyc

During the import process, Python was looking in project/ before snpp/ and finding an old snpp.pyc file. It would import the old pyc file and be satisfied, thus ignoring the entire snpp/ dir.

Had I been a little sharper (or a little more experienced with Python) I might have noticed that I was getting some strange import behavior in general whenever I tried to import anything from snpp/ . It should have occurred to me that the whole module was wonky, and not just the one function I was trying to use at the moment.

Answer 1

Check what exactly is being imported by using

snpp.__file__

right after import snpp statement.

Actually import might not be from the path you are expecting to see.