在Windows上使用全局包的virtualenv

Question

我安装了最新版本的virtualenv、django-nonrel、djangotoolbox和django_mongodb_engine。这个virtualenv是用-no-site-packages创建的。

我试着按照快速入门的步骤来操作，但在运行syncdb的时候遇到了以下错误：

Traceback (most recent call last):
  File "C:\www\environments\mongotest\djangomongo\manage.py", line 11, in <
module>
    execute_manager(settings)
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\__init__.py", line 438, in execute_manager
    utility.execute()
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\__init__.py", line 379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\__init__.py", line 261, in fetch_command
    klass = load_command_class(app_name, subcommand)
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\__init__.py", line 67, in load_command_class
    module = import_module('%s.management.commands.%s' % (app_name, name))
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\utils\import
lib.py", line 35, in import_module
    __import__(name)
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\commands\syncdb.py", line 7, in <module>
    from django.core.management.sql import custom_sql_for_model, emit_post_sync_
signal
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\core\managem
ent\sql.py", line 5, in <module>
    from django.contrib.contenttypes import generic
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\contrib\cont
enttypes\generic.py", line 6, in <module>
    from django.db import connection
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\db\__init__.
py", line 77, in <module>
    connection = connections[DEFAULT_DB_ALIAS]
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\db\utils.py"
, line 91, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "C:\Python25\lib\site-packages\django-1.2.3-py2.5.egg\django\db\utils.py"
, line 49, in load_backend
    raise ImproperlyConfigured(error_msg)
django.core.exceptions.ImproperlyConfigured: 'django_mongodb_engine' isn't an av
ailable database backend.
Try using django.db.backends.XXX, where XXX is one of:
    'dummy', 'mysql', 'oracle', 'postgresql', 'postgresql_psycopg2', 'sqlite3'
Error was: No module named django_mongodb_engine.base

看起来它在尝试使用默认的django安装，而不是我环境中的django-nonrel安装。

我试着添加了set PYTHONPATH=%PYTHONPATH%;C:\path\to\env\Lib\site-packages\django，但没有任何变化。

有没有人知道为什么这里会使用默认的django安装呢？

Answer 1

我来分享一下我对这个问题的看法：

如果你在用Eclipse这个软件，可以通过PyDev这个插件来解决这个问题。只需要把新的解释器指向你要用的新项目，就可以搞定了。

Answer 2

你试过运行 activate.bat 吗？

另外，我觉得设置 PYTHONPATH 应该可以解决问题，但你需要把新的路径放在最前面，而且这个路径应该指向包含 Django 安装文件的文件夹，而不是指向 Django 本身：

set PYTHONPATH=C:\path\to\env\Lib\site-packages\;%PYTHONPATH%

Answer 3

问题出在Windows的文件关联上。我当时想通过“manage.py syncdb”来同步数据库，这个命令用了默认的Windows Python安装。可是如果我用“python manage.py syncdb”，就能使用正确的Python和环境了。