Python 升级到Django 1.7：为翻译基础架构做好准备

我正在从Django 1.6升级到1.7，当我尝试执行

manage.py runserver

时，我得到以下跟踪：

Traceback (most recent call last):
  File "manage.py", line 9, in <module>
    execute_from_command_line(sys.argv)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute
    django.setup()
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/apps/config.py", line 87, in create
    module = import_module(entry)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/ben/Code/Repos/myrepo/myproject/core/mail/__init__.py", line 6, in <module>
    from myproject.core.mail.models import IMapEmailMessage, EmailStatus
  File "/home/ben/Code/Repos/myrepo/myproject/core/mail/models.py", line 20, in <module>
    from myproject.core.mail.utils import render_templates
  File "/home/ben/Code/Repos/myrepo/myproject/core/mail/utils.py", line 19, in <module>
    from myproject.core.util import clean_html
  File "/home/ben/Code/Repos/myrepo/myproject/core/util.py", line 1031, in <module>
    def make_url(url, text=_('here')):
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/utils/translation/__init__.py", line 83, in ugettext
    return _trans.ugettext(message)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", line 325, in ugettext
    return do_translate(message, 'ugettext')
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", line 306, in do_translate
    _default = translation(settings.LANGUAGE_CODE)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", line 209, in translation
    default_translation = _fetch(settings.LANGUAGE_CODE)
  File "/home/ben/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/utils/translation/trans_real.py", line 189, in _fetch
    "The translation infrastructure cannot be initialized before the "
django.core.exceptions.AppRegistryNotReady: The translation infrastructure cannot be initialized before the apps registry is ready. Check that you don't make non-lazy gettext calls at import time.

然而，我已经有了这些台词。在文件

myproject/core/util.py

中，我更改了以下行：

from django.utils.translation import ugettext as _

致：

---

这就把问题转移到了另一个使用

ugettext

的文件中。是否不再可以使用非惰性

ugettext

？或者我需要做一些设置来避免在导入时对其求值？

使用

make\u url（url，text=ugettext（'here'））

的问题是

text

的默认参数是在导入模块时求值的，而不是在

make\u url

函数运行时求值的

您还没有显示生成第二个错误的代码，所以我不知道它出了什么问题

可以在函数内部使用

ugettext

（只要该函数在导入期间不运行）。例如：

def make_url(url, text=None):
    if text is None:
        text = ugettext('here')

---

请注意，您仍然可以在代码中使用

导入uggettext作为

，我刚才使用了上面的

ugettext

来明确说明。

这不是答案！！为什么不想使用上一个版本？1.9我正在以增量方式升级到1.8，但试图先让1.7正常工作。我认为跟踪的最后一行很重要，“检查您在导入时没有进行非惰性gettext调用”。因此，是的，在导入时您需要惰性版本库！就这样。我只需要将

ugettext

更改为

ugettext\u lazy

，无论我在哪里遇到错误。幸运的是只有2例；大部分

ugettext

都像以前一样工作。

from django.utils.translation import ugettext_lazy as _

def make_url(url, text=None):
    if text is None:
        text = ugettext('here')