Django community: RSS
This page, updated regularly, aggregates Django Q&A from the Django community.
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How so I create a QRCode reader that reads the information and stores it in the database
I'm starting up a new project for an examination attendance that scans the qrcode of the students' identity card which contains the matriculation number and the full name information of the student. Is there a way to go about this because i am going to store the information inside the database and after the lecturer has logged in he scans twice the first time for sign-in and the second time for sign-out which would all be columns on the attendance table. Please what are your recommendations on how i should go about this project? -
settings.AUTH_USER_MODEL returns null from admin panel
I`m trying to import current user to my post model into author field But when i`m adding any post from admin panel, in author field i get '-' And i can`t figure out where problem is I`ve tried User and get_user_model and User but nothing is changed models.py: from django.db import models from django.conf import settings class Post(models.Model): title = models.CharField(max_length=50) date = models.DateField(auto_now_add=True) added_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE,null=True) content = models.TextField() attachment=models.FileField(upload_to='attachment',blank='True') def __str__(self): return self.title If i remove null=True - got error NOT NULL constraint failed How can i fix it?: I can`t post img, but there is django admin panel with '-' https://i.imgur.com/hTLsMoJ.png -
What's behind of the process of making changes "on the fly" in a HTML?
What happens behind in the browser level that allows making changes on the fly on HTML files, for example using javascript to add a class to an element, or even inserting a whole structure of elements? Does it refresh the page? Is it a language level or is it the browser saving some parameters and loading then when reloading the page? I have this doubt because after adding something, it doesn't reboot the other javascript modifications I've made, while for example, using django framework, when I load the same page again, all modifications made with js are gone. -
Django-filter: Change field_name of filter for foreign key field
This is with django 2 and django-filter 2 I want to rename a filter on django-filter for a Foreignk key field, so the query parameter has a better name. But If I put the same name as the field, it is not working, and returning the hole queryset, I have the following model class ActiveJob(models.Model): amount_to_pay=models.PositiveSmallIntegerField() post_category=models.ForeignKey(post_area) title = models.CharField(max_length=128) And I want to filter by the name field of post_category, with icontains. If I define the filter with the same name as the field in ActiveJob model, it is now working (it returns me the hole queryset !! ) With the two commented lines (in the filter definition down here) I want call like this, but it is not working, it returns the hole queryset: /?post_category=Telecommunications And with the filter defined only as category, I am calling like this, and it is working ok: /?category=Telecommunications This is the filter definition class ActiveJobFilter(filters.FilterSet): min_payment = filters.NumberFilter(field_name="amount_to_pay", lookup_expr="gte") max_payment = filters.NumberFilter(field_name="amount_to_pay", lookup_expr="lte") title = filters.CharFilter(lookup_expr='icontains') #post_category = filters.CharFilter(lookup_expr='icontains', field_name='post_category__name') category = filters.CharFilter(lookup_expr='icontains', field_name='post_category__name') class Meta: model = ActiveJob fields = [ "title", "category", # "post_category", "max_payment", ] -
How do I remove this error message in ModelForm?
I'm trying to create a way to update an item of the database that has the fields CharField and ForeignKey. I want to pass the original values so that they don't have to be manually entered for each field every time, but this gives me a "Select a valid choice. That choice is not one of the available choices." warning for the group field. How do I remove this warning message? Setting the error message (in ModelForm) to something else manually still displays an empty (unordered) list item. Setting the form in UpdateUserView to form = UserForm() gets rid of the errors, but doesn't pass default values to the form. models.py class User(models.Model): username = models.CharField(max_length=50) group = models.ForeignKey(Group, on_delete=models.CASCADE) class Group(models.Model): name = models.CharField(max_length=20) description = models.CharField(max_length=200) forms.py class UserForm(forms.ModelForm): class Meta: model = User fields = ['username', 'group'] views.py class UpdateUserView(TemplateView): template_name = 'update_user.html' def get(self, request): user_id = int(request.GET.get('user_id')) user = User.objects.get(id=user_id) default_name = getattr(user, 'username') default_group = getattr(user, 'group') form = UserForm({'username': default_name, 'group': default_group}) return render(request, self.template_name, {'form': form, 'user': user}) End Result -
How to have a Django relational database with four tables?
I am creating a website using Django and have a problem with the database! I have four tables (topics, questions, answers and images). Each one of these tables has an id column and I would like to connect these four tables together. I have tried to use a ForeignKey() but that didn't work out. I am receiving an error message. I don't know if I can use ManyToManyField() in this case, because it is only one column that I am trying to connect. This is the code: from django.db import models # Create your models here. class topics(models.Model): topic_id = models.AutoField(primary_key=True) topic_level = models.BooleanField() topic_name = models.TextField() class questions(models.Model): question_id = models.AutoField(primary_key=True) description = models.TextField() questions_type = models.BooleanField() class answers(models.Model): answer_id = models.AutoField(primary_key=True) description = models.TextField() class images (models.Model): image_id = models.AutoField(primary_key=True) image_blob = models.BinaryField() This is the code with the ForeignKey(): from django.db import models # Create your models here. class topics(models.Model): topic_id = models.AutoField(primary_key=True) topic_level = models.BooleanField() topic_name = models.TextField() topic_question = models.ForeignKey(questions, on_delete=CASCADE) topic_answer = models.ForeignKey(answers, on_delete=CASCADE) topic_image = models.ForeignKey(images, on_delete=CASCADE) class questions(models.Model): question_id = models.AutoField(primary_key=True) description = models.TextField() questions_type = models.BooleanField() question_topic = models.ForeignKey(topics, on_delete=CASCADE) question_answer = models.ForeignKey(answers, on_delete=CASCADE) question_image = models.ForeignKey(images, on_delete=CASCADE) class answers(models.Model): answer_id … -
django FormWizard (formtools) how to dynamically change form_list based on request?
Would appreciate any guidance on this. Have SessionWizardView from django-formtools and I want to be able to send in different forms based on which request.user.restaurant the user belongs to / request.site is being accessed. Different restaurants are going to have different sets of forms for the signup flow and I can't figure out how to accommodate this. It seems like I need to either pass in a list of firms in urls.py .as_view() or have the forms listed ahead of time in the class. MY_TEMPLATES = { '0': '/templates/wizard_1.html', '1': '/templates/wizard_2.html', '2': '/templates/wizard_3.html' } class MySignupWizard(SessionWizardView): form_list = [AddressForm, MenuForm, HoursForm,ContactForm] def get_template_names(self): return [MY_TEMPLATES[self.steps.current]] def done(self, form_list, **kwargs): etc. Since get_template_names(self) has access to self.request, and self.request.site, I think I could have MY_TEMPLATES be a nested dictionary, and pass in self.request.site along with the current step to these. Although is there a way to pass in data directly to these templates? Like do a query and pass in Restaurant data to each template? But I can't figure out how to dynamically modify form_list. There are the standard four forms above, but some restaurants only want three forms or slightly different forms. I'd like to do something like : restaurant … -
How can i redirect my homepage to my main domain using Django
I am trying to redirect my homepage url path https://www.va-glazing.com/home/ url to my main domain, which is https://www.va-glazing.com. I am hosting my site on python anywhere and got the domain from godaddy.com. thanks in advance! -
How could I get the latest blog posts for Mezzanine page?
I'm new on Mezzanine and I want to display the 8 latest post on a custom section of the home page. I already built the QuerySet: BlogPost.objects.filter(publish_date__isnull=False).order_by('-publish_date')[:8] I've already checked templates/blog/blog_post_list.html but I'm not clear on how can I pass the QuerySet result to the view. -
Django handling image using formset error
I am new to django formset, and now i wanted to get the image from an input file field . whenever i try to print the value of the cleaned_data i get none. # Create the formset, specifying the form and formset we want to use. PictureFormSet = formset_factory(PictureForm) profile_form = ProfileForm(request.POST, user=user) picture_formset = PictureFormSet(request.POST, request.FILES) if user.username == username: if request.method == 'POST': if profile_form.is_valid() and picture_formset.is_valid(): # save user info user.first_name = profile_form.cleaned_data.get('first_name') user.last_name = profile_form.cleaned_data.get('last_name') user.save() # now save data for picture_form for picture_f in picture_formset: picture = picture_f.cleaned_data.get('form-0-pic') proffession = picture_f.cleaned_data.get('form-0-proffession') print('=======================') print(picture) print(proffession) -
How and where should I create this transactional method?
I'm using Python 3.7. In a service class, I have these statements ... article.first_appeared_date = datetime.now(timezone.utc) article.save() ArticleStat.objects.save_main_article(article) The first pair of statements updates an attribute for a single object and the second statement creates a bunch of separate objects, using the first object. What i would like is for the whole thing to be executed as a transaction, whereby everything succeeds or no changes to the database occur if something fails. I'm unclear as to best practices in Python. Where would a method like this go? Does putting it in a manager class make it transactional? -
How to make django model choice field human readable
So I have django model choice field with months class EntrySummary(models.Model): JANUARY = '1' FEBRUARY = '2' MARCH = '3' APRIL = '4' MAY = '5' JUNE = '6' JULY = '7' AUGUST = '8' SEPTEMBER = '9' OCTOBER = '10' NOVEMBER = '11' DECEMBER = '12' MONTH_CHOICES = ( (JANUARY, 'January'), (FEBRUARY, 'February'), (MARCH, 'March'), (APRIL, 'April'), (MAY, 'May'), (JUNE, 'June'), (JULY, 'July'), (AUGUST, 'August'), (SEPTEMBER, 'September'), (OCTOBER, 'October'), (NOVEMBER, 'November'), (DECEMBER, 'December'), ) name = models.CharField( max_length=255 ) month = models.CharField( max_length=2, choices = MONTH_CHOICES, default=JANUARY, ) Views.py I render it def based_onmonth(request, *args, **kwargs): monthId = request.GET.get('month') monthEntry = EntrySummary.objects.filter(month=monthId) return render(request, 'app/js_templates/month_dropdown_list.html', {'MonthItem': monthId}) html template: <option value="">---------</option> {% for item in MonthItem %} <p>item.name</p> <option value="{{ item }}">{{ item }}</option> {% endfor %} Doing this i receive {'month': '2'} in my select section My question is how to print just 2 without month -
I am getting an "unable to import" error in django
I am Elvis, I am new to django and I am using Visual Studio Code. but everywhere that there is :"From django." I am getting the "[pyLint] unable to import 'django....' please help -
What could be the reason why css does not work in Chrome but works in Opera?
When I tried to add styles to the Django project, they do not work in Chrome, but work in Opera. CSS are very simple, for example, margin-top should be supported by any Chrome: https://www.w3schools.com/cssref/pr_margin-top.asp But Chrome does not see it, unlike the Opera. Tell me, please, what could be the problem? I took this project as a basis: https://developer.mozilla.org/en-US/docs/Learn/Server-side/Django/Home_page In locallibrary\catalog\static\css\styles.css I have following code: .sidebar-nav { margin-top: 20px; background-color: skyblue; padding: 0; list-style: none; } In locallibrary\catalog\templates\base_generic.html: {% load static %} link rel="stylesheet" href="{% static 'css/styles.css' %}"> "link rel..." start with "<" but it does not copy here. In locallibrary\locallibrary\settings.py: STATIC_URL = '/static/' -
AttributeError: 'Manager' object has no attribute
I'm using Python 3.7. I'm having a lot of trouble figuring out how and where I should put a method taht creates and saves multiple objets. I have this in my models.py file class ArticleStatManager(models.Manager): def save_main_article(self, article): Then in another part of the code, I call ArticleStat.objects.save_main_article(article) but this results in the error ArticleStat.objects.save_main_article(article) AttributeError: 'Manager' object has no attribute 'save_main_article' What am I doing wrong or where should I be placing this code so taht I can invoke it properly? -
Django - Custom Form does not prepopulate initial data
I have a parent model (Venue) and a child model (Amenity). A venue can have many amenities. while configuring my initial data and presenting it with {{form.as_p}} everything works as expected. But when I try to render my own custom form, so that I can apply a loop, It doesn't pre-populate them. Here is my template: <form method="POST" class="ui form"> {% csrf_token %} {% for category in categories %} <h4 class="ui horizontal divider header"> <i class="list icon"></i> {{category.category}} </h4> <p class="ui center aligned text"><u>{{category.description}}</u></p> {% for amenity in category.amenity_set.all %} <div class="inline field"> <label for="choices_{{amenity.id}}"></label> <div class="ui checkbox"> <input id="choices_{{amenity.id}}" type="checkbox" value="{{amenity.id}}" name="choices"> <label><span data-tooltip="{{amenity.description}}" data-position="top left">{{amenity}}</span></label> </div> </div> {% endfor %} {% endfor %} <button type="submit" name="submit" class="ui button primary">Next</button> </form> my ModelForm: class AmenitiesForm(ModelForm): class Meta: model = Venue fields = ('choices',) choices = forms.ModelMultipleChoiceField(Amenity.objects.all(), widget=forms.CheckboxSelectMultiple,) def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) if kwargs.get('instance'): initial = kwargs.setdefault('initial', {}) initial['choices'] = [c.pk for c in kwargs['instance'].amenity_set.all()] forms.ModelForm.__init__(self, *args, **kwargs) def save(self, commit=True): instance = forms.ModelForm.save(self) instance.amenity_set.clear() instance.amenity_set.add(*self.cleaned_data['choices']) return instance and my views.py: class AddAmenitiesView(LoginRequiredMixin, CreateView): """ AddAmenitiesView is the view that prompts the user to select the amenities of their venue. """ model = Venue form_class = AmenitiesForm template_name … -
Django duplicate database lookups with inlineformset
I need help with solving an issue regarding duplicate database query's for each form in an inlineformset. I have a page where users can add and edit books belonging to an author. models.py from django.db import models class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): author = models.ForeignKey(Author, on_delete=models.CASCADE) title = models.CharField(max_length=100) category_idcategory = models.ForeignKey(Category, models.DO_NOTHING) class Category(models.Model): name = models.CharField(max_length=100) forms.py from django import forms class BookForm(forms.ModelForm): class Meta: model = Books fields = '__all__' views.py instance = get_object_or_404(Author, id=id) form = inlineformset_factory(Author, Book, form=BookForm, can_delete=True, extra=5) formset = form(request.POST or None, instance=instance) if request.method == "POST": if formset.is_valid(): instanceForm = formset.save(commit=False) for obj in instanceForm: obj.save() for obj in formset.deleted_objects: obj.delete() return HttpResponseRedirect(URL) When I run the template, it performs a database query foreignkey relation to the Category model for each form in formset. How do I prevent those duplicates? I dont know where to put select_related or prefetch_related. If instances in Book model grows to a large number, the page load times are getting very slow. -
Async call and not wait while using pubnub with djagno
This is a module from PubNub that I'm using to publish a message to a topic from an API. By design I've kept the PubNub object singleton. class Pubnub: instance = None @classmethod def get(cls): if cls.instance is None: cls.instance = cls() return cls.instance def __init__(self): with open('config/config.yaml', 'r') as stream: try: conf = yaml.load(stream) pnconfig = PNConfiguration() pnconfig.subscribe_key = conf['pubnub']['publish_key'] pnconfig.publish_key = conf['pubnub']['subscribe_key'] pnconfig.ssl = False self.pubnub = PubNub(pnconfig) except yaml.YAMLError as e: pass def publish(self, channel): try: envelope = self.pubnub.publish().channel(channel).message({ 'message': True }).sync() print("publish timetoken: %d" % envelope.result.timetoken) except PubNubException as e: pass This is how I'm calling it, class SendCommunityTextMessage(views.APIView): def post(self, request, **kwargs): try: client_id = request.GET['client_id'] client_secret = request.GET['client_secret'] if Authenticator.authenticate_client(client_id, client_secret): try: //do something try: //do something more pubbub = Pubnub.get() pubbub.publish(receiver.hex_code) return Response({"Success": CommunityTextMessageSerializer(message).data}, status=status.HTTP_200_OK) except KeyError as e: return Response({"Failure": str(e)}, status=status.HTTP_400_BAD_REQUEST) except (User.DoesNotExist, CommunityRoom.DoesNotExist) as e: return Response({"Failure": str(e)}, status=status.HTTP_404_NOT_FOUND) else: return Response({"Failure": "Invalid client"}, status=status.HTTP_403_FORBIDDEN) except KeyError as _: return Response({"Failure": "Probably a typo, read the docs to use this API."}, status=status.HTTP_400_BAD_REQUEST) The issue is this slows down the API by minutes. How can I call the two lines, pubbub = Pubnub.get() pubbub.publish(receiver.hex_code) asynchronously and return out of the view … -
Django Unit Testing expected_url with random argument
I am trying to create a unit test for a view that will show a random object on a detail page. views.py def random_stuf(request): rand_stuf = Mod.objects.order_by('?').first().pk return HttpResponseRedirect(reverse('app:detail', args=(rand_stuf,))) urls.py path('detail/random/', views.random_stuf, name='random'), tests.py def test_random(self): response = self.client.get(reverse('app:random')) self.assertRedirects(response, '/detail/1/', status_code=302, target_status_code=200) the argument of the expected url will be different every time. Is there a way i can test this? -
Storing Objects in Algolia From Django
I just started with Algolia and Django and it seemed relatively easy to setup and define fine. Example of a user: from algoliasearch_django import AlgoliaIndex from algoliasearch_django.decorators import register from .models import User @register(User) class UserIndex(AlgoliaIndex): fields = ("id",'first_name', 'last_name', 'email', ''city', "state","zip_code", "phone_number") settings = {'searchableAttributes': ['first_name', 'last_name', 'email']} index_name = 'user_index' Except things started to break when I added fields that had relations to other fields: fields = ("id",'first_name', 'last_name', 'email', ''city', "state","zip_code", "phone_number", "jobs", "friends") jobs and friends both have their own models and pivot tables, and I often get errors such as Exception Value: Got AttributeError when attempting to get a value for field `id` on serializer `JobsSerializer`. The serializer field might be named incorrectly and not match any attribute or key on the `str` instance. Original exception text was: 'str' object has no attribute 'id'. What are some techniques of storing array or related values correctly in Algolia, and do it the "Django" way? -
Post comment inside Django DetailView
I need to add comments in article page. Post request receives data but not saves it. In models.py: class TemporaryComment(models.Model): article = models.ForeignKey(Article, on_delete=models.CASCADE, related_name='temporary_comment') email = models.EmailField() message = models.TextField(max_length=1500) timestamp = models.DateTimeField(auto_now_add=True) is_approved = models.BooleanField(default=True) In forms.py: class CommentModelForm(forms.ModelForm): class Meta: model = TemporaryComment fields = [ 'article', 'email', 'message', ] in views.py: class ArticleDetailView(FormMixin, DetailView): model = Article template_name = 'article.html' form_class = CommentModelForm def get_success_url(self): return reverse_lazy('main:article', kwargs={'pk': self.object.pk}) def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) context['last_articles'] = Article.objects.filter(is_active=True).order_by('-timestamp')[:10] context['comments'] = self.object.temporary_comment.filter(is_approved=True) context['form'] = self.get_form() return context def post(self, request, *args, **kwargs): self.object = self.get_object() form = self.get_form() if form.is_valid(): return self.form_valid(form) else: return self.form_invalid(form) def form_valid(self, form): form.save() return super().form_valid(form) If i comment out article field in forms.py, i got this error: null value in column "article_id" violates not-null constraint. DETAIL: Failing row contains (18, username@email.com, check message, 2019-01-20 18:35:36.615955+00, t, null).. Help will be gladly accepted. Thanks for your time. -
after open localhost error occured, no module named urls
ImportError at / No module named urls Request Method: GET Request URL: http://localhost/ Django Version: 1.8.7 Exception Type: ImportError Exception Value: No module named urls Exception Location: /home/arunima/Desktop/mysite/tutorial/tutorial/urls.py in , line 17 Python Executable: /home/arunima/Desktop/mysite/tutorial/bin/python Python Version: 2.7.12 Python Path: ['/home/arunima/Desktop/mysite', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-i386-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/home/arunima/Desktop/mysite/tutorial'] Server time: Sun, 20 Jan 2019 18:36:36 +0000 -
Serve protected files to users
I am in process of making users able to download their project files in a protected manner using Nginx. I know how to setup a protection location in Nginx, but how do I configure django to tell Nginx this is the file the user is requesting? I currently have a download button in my HTML that is linked to the corresponding database column with the path to their file. How do I tell Nginx that the Href field i've added is the path to the file it should serve the user and obfuscate the link, so they don't have my system path to the file? <td><a href="{{ item.OutputPath }}">Download</a> </tr> -
Group by title in template
I try to display data from db and place them under correct title. models.py class Game(models.Model): location= models.ForeignKey('location', on_delete=models.CASCADE') group = models.IntegerField() firstname = models.CharField() surname = models.CharField() views.py class group(generic.CreateView): template_name = 'group.html' def get(self, request, *args, **kwargs): game = Game.objects.filter(location__type__pk=kwargs['pk']).order_by('location__pk', 'group') context = { 'game': game, } return render(request, self.template_name, context) Lets say that the 'group' can be like A, B, C etc. In the template I want to display it like Location Foo Group A Jonas Andersson Lisa Silverspoon Group B Sven Bohlin Göran Lantz Location Bar Group A Mia Milakovic Lars Larsson Group B Anna Annasdotter I have tried with so many variants of for-loops without any success. Is it possible? Can you do this? -
Create nested objects in django rest framework
I'm trying to create nested objects in Django Rest Framework according to the docs. Here's my models.py: import uuid from django.db import models from django.utils.http import int_to_base36 from django.core.validators import MaxValueValidator, MinValueValidator from django.contrib.auth import get_user_model ID_LENGTH = 12 USER = get_user_model() def slug_gen(): """Generates a probably unique string that can be used as a slug when routing Starts with a uuid, encodes it to base 36 and shortens it """ #from base64 import b32encode #from hashlib import sha1 #from random import random slug = int_to_base36(uuid.uuid4().int)[:ID_LENGTH] return slug class List(models.Model): """Models for lists """ slug = models.CharField(max_length=ID_LENGTH, default=slug_gen, editable=False) id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) created_by = models.ForeignKey(USER, on_delete=models.CASCADE, related_name='list_created_by') created_at = models.DateTimeField(auto_now_add=True) modified_by = models.ForeignKey(USER, on_delete=models.SET_NULL, null=True, related_name='list_modified_by') modified_at = models.DateTimeField(auto_now_add=True) title = models.CharField(max_length=255) description = models.CharField(max_length=255, blank=True, default='') is_public = models.BooleanField(default=False) def __str__(self): return self.title class Item(models.Model): """Models for list items """ slug = models.CharField(max_length=ID_LENGTH, default=slug_gen, editable=False) id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) modified_at = models.DateTimeField(auto_now_add=True) title = models.CharField(max_length=255) description = models.CharField(max_length=255, blank=True, default='') list = models.ForeignKey(List, on_delete=models.CASCADE, related_name='items') order = models.IntegerField(validators=[MinValueValidator(1), MaxValueValidator(10)]) class Meta: unique_together = ('list', 'order') ordering = ['order'] def __unicode__(self): return '%d: %s' % (self.order, self.title) Here's my serializers.py: class ItemSerializer(serializers.ModelSerializer): class Meta: model = Item …
