Python论坛的帖子：

星期二十一月 20 09:05:12 HKT 2007

（1）情况大概这样的，我弄了一个django项目，其中urls.py有大概这么几句：
(r"^where/list/$",  "webui.views.where_list"),
(r"^where/detail/(?P.+)/$",  "webui.views.where_detail"),


（2）在webui/views.py里面这样定义
@login_required
def where_list(request):
    ...

@login_required
def where_detail(request, ...):
    ...

traceback.print_stack()
print id(where_detail)

（3）在templates用
{% url webui.views.where_list %}
可以正确生成
/where/list/

（4）在models里面这样定义：
class Where(models.Model):
    id = models.CharField(.........)
    ...

    @models.permalink
    def get_absolute_url(self):
        return ("webui.views.where_detail", (), {"where_id":self.id})

（5）但这个get_absolute_url()无法返回正确的url，总是出现NoReverseMatch异常。


（6）后来发现，程序运行后处理第一个请求时，打印了2次where_detail的id值，显然这个views被import了2次，居然是两个不同的id值:
140185036

140461068

也就是说，程序内部出现了2个where_detail的函数对象……

（7）两次print_stack()的结果都是相同：
  File
"/home/bullshit/workspace/django_svn/django/core/management/commands/runserver.py",
line 54, in inner_run
    run(addr, int(port), handler)
  File
"/home/bullshit/workspace/django_svn/django/core/servers/basehttp.py", line
651, in run
    httpd.serve_forever()
  File "SocketServer.py", line 201, in serve_forever
    self.handle_request()
  File "SocketServer.py", line 222, in handle_request
    self.process_request(request, client_address)
  File "SocketServer.py", line 241, in process_request
    self.finish_request(request, client_address)
  File "SocketServer.py", line 254, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File
"/home/bullshit/workspace/django_svn/django/core/servers/basehttp.py", line
543, in __init__
    BaseHTTPRequestHandler.__init__(self, *args, **kwargs)
  File "SocketServer.py", line 522, in __init__
    self.handle()
  File
"/home/bullshit/workspace/django_svn/django/core/servers/basehttp.py", line
588, in handle
    handler.run(self.server.get_app())
  File
"/home/bullshit/workspace/django_svn/django/core/servers/basehttp.py", line
278, in run
    self.result = application(self.environ, self.start_response)
  File
"/home/bullshit/workspace/django_svn/django/core/servers/basehttp.py", line
620, in __call__
    return self.application(environ, start_response)
  File "/home/bullshit/workspace/django_svn/django/core/handlers/wsgi.py",
line 205, in __call__
    response = self.get_response(request)
  File "/home/bullshit/workspace/django_svn/django/core/handlers/base.py",
line 81, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File
"/home/bullshit/workspace/django_svn/django/contrib/auth/decorators.py",
line 62, in __call__
    return self.view_func(request, *args, **kwargs)
  File
"/home/bullshit/workspace/bukson_datain/../bukson_datain/datain/views.py",
line 74, in create_where
    return create_object(request, model=Where)
  File
"/home/bullshit/workspace/django_svn/django/views/generic/create_update.py",
line 50, in create_object
    return HttpResponseRedirect(new_object.get_absolute_url())
  File "/home/bullshit/workspace/django_svn/django/utils/functional.py",
line 3, in _curried
    return _curried_func(*(args+moreargs), **dict(kwargs, **morekwargs))
  File "/home/bullshit/workspace/django_svn/django/db/models/base.py", line
473, in get_absolute_url
    return settings.ABSOLUTE_URL_OVERRIDES.get('%s.%s' % (opts.app_label,
opts.module_name), func)(self)
  File "/home/bullshit/workspace/django_svn/django/db/models/__init__.py",
line 32, in inner
    return reverse(bits[0], None, *bits[1:3])
  File "/home/bullshit/workspace/django_svn/django/core/urlresolvers.py",
line 301, in reverse
    return iri_to_uri(u'/' + get_resolver(urlconf).reverse(viewname, *args,
**kwargs))
  File "/home/bullshit/workspace/django_svn/django/core/urlresolvers.py",
line 279, in reverse
    lookup_view = get_callable(lookup_view, True)
  File "/home/bullshit/workspace/django_svn/django/utils/functional.py",
line 18, in wrapper
    result = func(*args)
  File "/home/bullshit/workspace/django_svn/django/core/urlresolvers.py",
line 47, in get_callable
    lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
  File
"/home/bullshit/workspace/bukson_datain/../bukson_datain/datain/views.py",
line 111, in 
    traceback.print_stack()

（8）跟踪permalink里面用到的revers函数，里面有一个views函数到url的revers_dict，通过对比id值，发觉它使用了第一次import时的where_detail对象。


疑问：
（a）为什么程序运行后，处理第一个请求时会出现了2个不同的views函数对象？
（b）没有没兄弟成功使用过这个函数……

我的环境是 kubuntu 7.10 + python 2.5.1 + django-svn今天check out的代码
-------------- 下一部分 --------------
一个HTML附件被移除...
URL: http://python.cn/pipermail/python-chinese/attachments/20071120/d0534ea1/attachment-0001.html

标题：[python-chinese] permalink遇到的怪问题