'NoneType'オブジェクトに 'name'属性がありません

Question

私はワインの推奨システムを構築しようとしています。 reviews/view.pyページでは、私はこのエラーを得た：

from django.shortcuts import get_object_or_404, render 
from django.http import HttpResponseRedirect 
from django.core.urlresolvers import reverse 
from django.contrib.auth.models import User 
from .models import Review, Wine, Cluster 
from .forms import ReviewForm 
from .suggestions import update_clusters 

import datetime 

from django.contrib.auth.decorators import login_required 


def review_list(request): 
    latest_review_list = Review.objects.order_by('-pub_date')[:9] 
    context = {'latest_review_list': latest_review_list} 
    return render(request, 'reviews/review_list.html', context) 


def review_detail(request, review_id): 
    review = get_object_or_404(Review, pk=review_id) 
    return render(request, 'reviews/review_detail.html', {'review': review}) 


def wine_list(request): 
    wine_list = Wine.objects.order_by('-name') 
    context = {'wine_list': wine_list} 
    return render(request, 'reviews/wine_list.html', context) 


def wine_detail(request, wine_id): 
    wine = get_object_or_404(Wine, pk=wine_id) 
    form = ReviewForm() 
    return render(request, 'reviews/wine_detail.html', {'wine': wine, 'form': form}) 


@login_required 
def add_review(request, wine_id): 
    wine = get_object_or_404(Wine, pk=wine_id) 
    form = ReviewForm(request.POST) 
    if form.is_valid(): 
     rating = form.cleaned_data['rating'] 
     comment = form.cleaned_data['comment'] 
     user_name = request.user.username 
     review = Review() 
     review.wine = wine 
     review.user_name = user_name 
     review.rating = rating 
     review.comment = comment 
     review.pub_date = datetime.datetime.now() 
     review.save() 
     update_clusters() 
     # Always return an HttpResponseRedirect after successfully dealing 
     # with POST data. This prevents data from being posted twice if a 
     # user hits the Back button. 
     return HttpResponseRedirect(reverse('reviews:wine_detail', args=(wine.id,))) 

    return render(request, 'reviews/wine_detail.html', {'wine': wine, 'form': form}) 


def user_review_list(request, username=None): 
    if not username: 
     username = request.user.username 
    latest_review_list = Review.objects.filter(user_name=username).order_by('-pub_date') 
    context = {'latest_review_list': latest_review_list, 'username': username} 
    return render(request, 'reviews/user_review_list.html', context) 


@login_required 
def user_recommendation_list(request): 
    # get request user reviewed wines 
    user_reviews = Review.objects.filter(user_name=request.user.username).prefetch_related('wine') 
    user_reviews_wine_ids = set(map(lambda x: x.wine.id, user_reviews)) 

    # get request user cluster name (just the first one righ now) 
    try: 
     user_cluster_name = \ 
      User.objects.get(username=request.user.username).cluster_set.first().name 
    except: # if no cluster has been assigned for a user, update clusters 
     update_clusters() 
     user_cluster_name = \ 
      User.objects.get(username=request.user.username).cluster_set.first().name 

    # get usernames for other memebers of the cluster 
    user_cluster_other_members = \ 
     Cluster.objects.get(name=user_cluster_name).users \ 
      .exclude(username=request.user.username).all() 
    other_members_usernames = set(map(lambda x: x.username, user_cluster_other_members)) 

    # get reviews by those users, excluding wines reviewed by the request user 
    other_users_reviews = \ 
     Review.objects.filter(user_name__in=other_members_usernames) \ 
      .exclude(wine__id__in=user_reviews_wine_ids) 
    other_users_reviews_wine_ids = set(map(lambda x: x.wine.id, other_users_reviews)) 

    # then get a wine list including the previous IDs, order by rating 
    wine_list = sorted(
     list(Wine.objects.filter(id__in=other_users_reviews_wine_ids)), 
     key=lambda x: x.average_rating, 
     reverse=True 
    ) 

    return render(
     request, 
     'reviews/user_recommendation_list.html', 
     {'username': request.user.username, 'wine_list': wine_list} 
    ) 

Answer 1

ほとんどの場合、あなたのコード：

'NoneType' object has no attribute 'name' 

これは、私はこれらのエラー

User.objects.get(username=request.user.username).cluster_set.first().name 

はここで完全なコードで得たラインでしたupdate_clustersメソッドは、ユーザーのクラスタを作成していません。特定のユーザーのクラスタオブジェクトを実際に作成していることを確認してください。それでも疑わしい場合は、その関数のコードも記述してください。ここで

Answer 2

はupdate_clusterのコード（）

def update_clusters(): 
    num_reviews = Review.objects.count() 
    update_step = ((num_reviews/100) + 1) * 5 
    if num_reviews % update_step == 0: # using some magic numbers here, sorry... 
     # Create a sparse matrix from user reviews 
     all_user_names = map(lambda x: x.username, User.objects.only("username")) 
     all_wine_ids = set(map(lambda x: x.wine.id, Review.objects.only("wine"))) 
     num_users = len(all_user_names) 
     ratings_m = dok_matrix((num_users, max(all_wine_ids) + 1), dtype=np.float32) 
     for i in range(num_users): # each user corresponds to a row, in the order of all_user_names 
      user_reviews = Review.objects.filter(user_name=all_user_names[i]) 
      for user_review in user_reviews: 
       ratings_m[i, user_review.wine.id] = user_review.rating 

     # Perform kmeans clustering 
     k = int(num_users/10) + 2 
     kmeans = KMeans(n_clusters=k) 
     clustering = kmeans.fit(ratings_m.tocsr()) 

     # Update clusters 
     Cluster.objects.all().delete() 
     new_clusters = {i: Cluster(name=i) for i in range(k)} 
     for cluster in new_clusters.values(): # clusters need to be saved before refering to users 
      cluster.save() 
     for i, cluster_label in enumerate(clustering.labels_): 
      new_clusters[cluster_label].users.add(User.objects.get(username=all_user_names[i])) 

Answer 3

CLUSTER_SETが空です。変数を使用しようとする前に、変数がNoneと等しくないことを確認する必要があります。