Python导入-参考顶层模块，而不是“层内”模块

Question

Python v2.7

Directory Structure :

- project
  - manage.py
  - utils
    - __init__.py
    - somescript.py
  - apps
    - __init__.py
    - someapp
      - views.py
      - utils.py

project.apps.someapp.views :

// imports
from utils import somescript

// rest of the stuff

Raises ImportError: cannot import name somescript

Tried a dotted relative import:

// imports

from ...utils import somescript

// rest of the stuff

This raises ValueError: Attempted relative import beyond toplevel package .

This is a Django project. It runs through manage.py .
Command : ./manage.py runserver 0:41000

Answer 1

I'm a bit suprised someone like Daniel Roseman advise you to rename one of your modules when this issue has long been solved by providing support for absolute imports in py2 via the __future__ lib.

All you need is to add this at the top of your module (before any other statement):

from __future__ import absolute_import

From there on, all non explicitely relative imports will be treated as absolute (ie as in py3), so in apps.someapp.views, you can do:

from __future__ import absolute_import
import utils # => project.utils
from . import utils as local_utils # => apps.someapp.utils

NB: note that __future__ directives only affect the current module, your other modules will remain unaffected.

NB2: you may want to have a look at __future__.unicode_literals too - it makes life much easier in django projects which mostly expect unicode everywhere.

Answer 2

As @Daniel Roseman suggested you should upgrade to Python 3.

However this isn't always possible, or at least not possible right now.

There is a Python built-in module imp . You can use it to manually import the files you need.

Here is an example how it could work:

project.apps.someapp.views

import imp
somescript = imp.load_source('utils.somescript', 'path/to/utils/somescript.py')

Now you can use somescript in your views.py . It's not the nicest solution, but it might help you to bridge the gap until you're ready to upgrade your codebase to Python 3.

Also please take care to specify the filepath in a flexible way, without hard coding.