无法导入设置；不在系统路径上

Question

我想让Django用virtualenv工作。我已经在网上找到了hello world页面。但是，现在似乎出现了一些错误，因为我的大多数命令都给出了关于myProject.settings的相同错误

(myenv)user@mint /opt/myenv/myProject $ python manage.py startapp polls
Traceback (most recent call last):
  File "manage.py", line 13, in <module>
    execute_from_command_line(sys.argv)
  File "/opt/myenv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 453, in execute_from_command_line
    utility.execute()
  File "/opt/myenv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 392, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/opt/myenv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 263, in fetch_command
    app_name = get_commands()[subcommand]
  File "/opt/myenv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 109, in get_commands
    apps = settings.INSTALLED_APPS
  File "/opt/myenv/local/lib/python2.7/site-packages/django/conf/__init__.py", line 53, in __getattr__
    self._setup(name)
  File "/opt/myenv/local/lib/python2.7/site-packages/django/conf/__init__.py", line 48, in _setup
    self._wrapped = Settings(settings_module)
  File "/opt/myenv/local/lib/python2.7/site-packages/django/conf/__init__.py", line 134, in __init__
    raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'myProject.settings' (Is it on sys.path?): No module named myProject.settings
(myenv)user@mint /opt/myenv/myProject $ 

Answer 1

你试过这样的东西吗？也许会有用。

python manage.py startapp polls --settings=myProject.settings

Answer 2

python必须导入您的settings.py。这可以通过几种方式实现：

• 如@amyangfei所述，您的PYTHONPATH环境中有包含myProject的文件夹，即sys.path

注意，^{}是python用来构建这个sys.path的系统环境变量，它的修改依赖于os。对于mac os，请参见this reference；对于windows，请参见this。注意，PYTHONPATH仅用于构造sys.path，其随os.environ['PYTHONPATH']=<some_new_value>的变化没有显著影响。

但是，可以动态修改sys.path，以帮助import模块查找所需的包，请参见以下示例：

$ mkdir /tmp/tst
$ echo "print 'test'" > /tmp/tst/__init__.py
$ python -c "import tst"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named tst
$ python -c "import os; os.environ['PYTHONPATH']+=';/tmp'; import tst;"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named tst
$ python -c "import sys; sys.path.append('/tmp'); import tst;"
test
$ export PYTHONPATH=$PYTHONPATH:/tmp/
$ python -c "import tst"
test

• 您可以从包含myProject的文件夹中运行python manage.py。

为了让后者发挥作用，您的项目结构必须如下所示：

manage.py
myProject/
    settings.py

• 最后一个选项是，如果manage.py和settings.py位于同一位置，请将环境变量DJANGO_SETTINGS_MODULE更改为settings，而不是myProject.settings，或者使用--settings=settings参数运行python manage.py。

Answer 3

检查python sys.path中是否有'/opt/myenv/myProject'。 （参见python doc:sys.path[0]）是包含用于调用python解释器的脚本的目录。如果脚本目录不可用（例如，如果以交互方式调用解释器或从标准输入读取脚本），则路径[0]是空字符串（http://docs.python.org/2/library/sys.html#sys.path）

➜  mysite  python
Python 2.6.8 (unknown, Aug 25 2013, 00:04:29) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print sys.path
['', '/Users/xxx/xxx/', ... ]

类似的问题：ImportError: Could not import settings，Could not import settings 'myproject.settings' (Is it on sys.path?): No module named pinax