Django - AttributeError => 'set' object has no attribute 'get'

问题

I'm going through the book Django 1.0 Website Development where you build a small social bookmarking application. I'm at chapter 5 where you create a form to add bookmarks and although I've followed the instructions and have been struggling on this error for days. I get the error:

AttributeError at /save/
'set' object has no attribute 'get'

The error is being thrown on line 6 of the template {{ form.as_p }}

The views.py code is:

def bookmark_save_page(request):
    if request.method == 'POST':
        form = BookmarkSaveForm(request)
        if form.is_valid():
            # create or get link.
            link, dummy = Link.objects.get_or_create(
                url=form.cleaned_data['url']
            )
            # create or get bookmark.
            bookmark, created = Bookmark.objects.get_or_create(
                user=request.user,
                link=link
            )
            # if bookmark is being updated, clear the old tag list
            if not created:
                bookmark.tag_set.clear()
            # create new tag list
            tag_names = form.cleaned_data['tags'].split()
            for tag_name in tag_names:
                tag, dummy = Tag.objects.get_or_create(name=tag_name)
                bookmark.tag_set.add()
            # save bookmark to database
            bookmark.save()
            return HttpResponseRedirect(
                '/user/%s/' % request.user.username
            )
        else:
            form = BookmarkSaveForm()
            variables = RequestContext(request, {
                'form' : form
            })
            return render_to_response('bookmark_save.html', variables)

And the template code is:

{% extends "base.html" %}
{% block title %}Save Bookmark{% endblock %}
{% block head %}Save Bookmark{% endblock %}
{% block content %}
<form method="post" action=".">{% csrf_token %}
    **{{ form.as_p }}**
    <input type="submit" value="save" />
</form>
{% endblock %}

Any help would be much appreciated as I'm stuck at this point in the book and can't seem to find an answer. Thanks!

回答1:

Is this an error for you?

for tag_name in tag_names:
    tag, dummy = Tag.objects.get_or_create(name=tag_name)
    bookmark.tag_set.add()  # not adding the tag?

Shouldn't it be: bookmark.tag_set.add(tag) ? The .add() doesn't actually cause an error, but I know you aren't adding your tag.

Without seeing the traceback, I'm guessing.

My other guess is that you might be using the RequestContext wrong?

return render_to_response('bookmark_save.html',
                              {'form': form},
                              context_instance=RequestContext(request))

I believe the way you are using it now is meant for the non-shortcut approach of using an HttpResponse()

来源：https://stackoverflow.com/questions/10406606/django-attributeerror-set-object-has-no-attribute-get