Django ImportError：无法导入设置

我试图在Django中开发一个示例项目，但在运行syncdb命令时遇到错误.

我的项目 struct 如下所示:

/用户/django_演示/godjango/预订:

manage.py
    registration/
        forms.py
        views.py
        models.py
        urls.py
    bookings/
        settings.py
        urls.py

我的manage.py文件如下所示:

#!/usr/bin/env python
import os
import sys

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "bookings.settings")
    from django.core.management import execute_from_command_line
    execute_from_command_line(sys.argv)

我的PYTHONPATH和DJANGO_SETTINGS_MODULE设置如下

$echo $DJANGO_SETTINGS_MODULE
bookings.settings

$ echo $PYTHONPATH
/Users/django_demo/godjango/bookings

还有我的WSGI.py文件如下所示:

 import os
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "bookings.settings")
 from django.core.wsgi import get_wsgi_application
 application = get_wsgi_application()

当我运行python manage.py syncdb命令时，我收到以下错误.

Traceback (most recent call last):
  File "manage.py", line 11, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 443, in execute_from_command_line
    utility.execute()
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 261, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/__init__.py", line 69, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/commands/syncdb.py", line 8, in <module>
    from django.core.management.sql import custom_sql_for_model, emit_post_sync_signal
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/core/management/sql.py", line 6, in <module>
    from django.db import models
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/db/__init__.py", line 11, in <module>
    if DEFAULT_DB_ALIAS not in settings.DATABASES:
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/utils/functional.py", line 184, in inner
    self._setup()
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/conf/__init__.py", line 42, in _setup
    self._wrapped = Settings(settings_module)
  File "/Users/django_demo/godjango/lib/python2.7/site-packages/django/conf/__init__.py", line 95, in __init__
    raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'bookings.settings' (Is it on sys.path?): No module named unipath

有人能告诉我我错过了什么吗？