Question

我的views.py是

def editbook(request,book_id):
    log.debug("test....")
    if request.POST:
        book_name =request.POST['book_name']
        publisher_name =request.POST['publisher_name']
    books=Book.objects.filter(book_id=book_id).update(book_name=book_name, publisher_name=publisher_name)
    first_name = request.POST('first_name')
        last_name = request.POST('last_name')
        email = request.POST('email')
        age = request.POST('age')

    author_info = Author.objects.latest('author_id')
    log.debug("test:%s",author_info.author_id)
    author = Author.objects.filter(author_id=author_info.author_id).update(first_name = first_name,last_name = last_name,email=email,age=age)
        return redirect('/index/')
    else:
        books = Book.objects.get(pk=book_id)
        return render_to_response('editbook.html',{'books':books},{'author':author},context_instance=RequestContext(request))

我收到错误

"Traceback (most recent call last):
  File "/usr/local/lib/python2.6/site-packages/django/core/handlers/base.py", line 111, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "/root/Samples/DemoApp/DemoApp/views.py", line 70, in editbook
    return render_to_response('editbook.html',{'books':books},{'author':author},context_instance=RequestContext(request))
UnboundLocalError: local variable 'author' referenced before assignment.

Answer 1

看起来你在if子句中分配了作者值，同时在else块中返回它。该错误只是在说你执行了else块（例如request.POST是None）。我需要的是在if语句之前添加默认值或移动赋值。例如，您可以执行以下操作：

def editbook(request, book_id):
    log.debug("test....")
    author = Author.objects.filter(author_id=author_info.author_id)
    books=Book.objects.filter(book_id=book_id)
    if request.POST:
        book_name =request.POST['book_name']
        publisher_name =request.POST['publisher_name']
        books=Book.objects.filter(book_id=book_id).update(book_name=book_name, publisher_name=publisher_name)
        first_name = request.POST('first_name')
        last_name = request.POST('last_name')
        email = request.POST('email')
        age = request.POST('age')

        author_info = Author.objects.latest('author_id')
        log.debug("test:%s",author_info.author_id)
        author = Author.objects.filter(author_id=author_info.author_id).update(first_name = first_name,last_name = last_name,email=email,age=age)
        return redirect('/index/')
    else:
        books = Book.objects.get(pk=book_id)
        return render_to_response('editbook.html',{'books':books},{'author':author},context_instance=RequestContext(request))

Answer 2

您的代码格式有点偏，但如果author语句为true，则If只会被赋予一个值。如果它是假的，那么当它尚未设置时，你试图返回author值。

Answer 3

您的问题是author仅在if条件为真时定义，但您在else块中使用它，该块将在if条件下运行失败。它与此相同：

def foo(z=None):
    if z:
        i = 'hello'
    else:
        print i


foo()

执行上述操作时，由于z为None，if条件失败，i未分配值。由于if条件失败，运行else子句，尝试打印尚未定义的i。

在赋值之前引用的局部变量“author”

3 个答案: