找不到原因「類型錯誤：強迫爲Unicode：需要字符串或緩衝區，NoneType發現」

Question

我越來越從生產服務器這個錯誤：

File "/home/example/svn/libs/django/core/handlers/base.py", line 100, in get_response 
    response = callback(request, *callback_args, **callback_kwargs) 

File "/home/example/svn/src/app/../app/libs/auth/decorators.py", line 125, in __call__ 
    return self.view_func(request, *args, **kwargs) 

File "/home/example/svn/src/app/../app/membership/decorators.py", line 64, in __call__ 
    return self.view_func(request, *args, **kwargs) 

File "/home/example/svn/src/app/../app/site/views/system/invoices.py", line 168, in send_via_email_form 
    return SendViaEmailFormPage(request, pk, what, sending_type).custom() 

File "/home/example/svn/src/app/../app/security/security.py", line 99, in execute 
    return func(*args, **kw) 

File "/home/example/svn/src/app/../app/site/views/system/invoices.py", line 405, in custom 
    return self.custom_response or self.response() 

File "/home/example/svn/src/app/../app/security/security.py", line 99, in execute 
    return func(*args, **kw) 

File "/home/example/svn/src/app/../app/libs/pages/__init__.py", line 235, in response 
    response = render_to_response(self.template, self.data, context_instance=RequestContext(self.request, self.data)) 

File "/home/example/svn/libs/django/shortcuts/__init__.py", line 20, in render_to_response 
    return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs) 

File "/home/example/svn/libs/django/template/loader.py", line 186, in render_to_string 
    return t.render(context_instance) 

File "/home/example/svn/libs/django/template/__init__.py", line 173, in render 
    return self._render(context) 

File "/home/example/svn/libs/django/template/__init__.py", line 167, in _render 
    return self.nodelist.render(context) 

File "/home/example/svn/libs/django/template/__init__.py", line 796, in render 
    bits.append(self.render_node(node, context)) 

File "/home/example/svn/libs/django/template/__init__.py", line 809, in render_node 
    return node.render(context) 

File "/home/example/svn/libs/django/template/__init__.py", line 849, in render 
    return _render_value_in_context(output, context) 

File "/home/example/svn/libs/django/template/__init__.py", line 829, in _render_value_in_context 
    value = force_unicode(value) 

File "/home/example/svn/libs/django/utils/encoding.py", line 66, in force_unicode 
    s = unicode(s) 

TypeError: coercing to Unicode: need string or buffer, NoneType found 

Unfortunely我不能在任何重現開發服務器上的方式。這個例外沒有什麼幫助。從Django中代碼：

if hasattr(s, '__unicode__'): 
    s = unicode(s) 

如果爲何NoneType發現它具有 '的unicode' 屬性。我是否需要深入研究這個python源代碼？將不勝感激任何幫助。

謝謝。

Answer 1

專注於追蹤的這一部分。這看起來像你寫的代碼。

File "/home/example/svn/src/app/../app/membership/decorators.py", line 64, in __call__ 
    return self.view_func(request, *args, **kwargs) 

File "/home/example/svn/src/app/../app/site/views/system/invoices.py", line 168, in send_via_email_form 
    return SendViaEmailFormPage(request, pk, what, sending_type).custom() 

File "/home/example/svn/src/app/../app/security/security.py", line 99, in execute 
    return func(*args, **kw) 

File "/home/example/svn/src/app/../app/site/views/system/invoices.py", line 405, in custom 
    return self.custom_response or self.response() 

File "/home/example/svn/src/app/../app/security/security.py", line 99, in execute 
    return func(*args, **kw) 

File "/home/example/svn/src/app/../app/libs/pages/__init__.py", line 235, in response 
    response = render_to_response(self.template, self.data, context_instance=RequestContext(self.request, self.data)) 

某處有一個None應該有一個字符串。

在很多情況下，這是因爲有一個未經身份驗證的用戶，默認匿名用戶有時缺少您的「真實」用戶擁有的各種屬性值。它在開發中沒有問題，因爲您的開發PC上有允許您登錄的cookie。您可能會缺少生產服務器中的一些cookie，並且沒有登錄。

它有助於將大量的日誌輸出添加到涉及的視圖函數中，以便您可以通讀Apache日誌並讀取看看事情正在破裂。