Django community: Django Q&A RSS
This page, updated regularly, aggregates Django Q&A from the Django community.
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what is defference between django rest framwork's 'serializer' and 'serializer fields'
The serializer of django rest framework converts the model data to JSON format and validates incoming data Check function. The functions of the serializer fields are to convert values and data types and to validate input values. I think it looks the same, but I wonder what the difference is. -
How to remove some warning messages using Django and Python
I need some help. I am getting some warning messages while formatting my code using pylint. I am explaining those warning messages below. C: 77, 0: Line too long (82/80) (line-too-long) C:125, 0: Line too long (83/80) (line-too-long) E: 76,13: Class 'Service' has no 'objects' member (no-member) E:106,19: Class 'Personal' has no 'objects' member (no-member) I am explaining my code below. def view_service(request): """ This function helps to display the past booking items""" people = Service.objects.all() return render(request, 'bookingservice/view_service.html', {'people': people}) models.py: class Service(models.Model): """In this class the columns for service table has declared""" cname = models.CharField(max_length=200) date_of_service = models.DateTimeField(default=datetime.now, blank=True) vechile_no = models.CharField(max_length=200) service_type = models.CharField(max_length=200) class Personal(models.Model): """In this class the columns for Person table has declared""" name = models.CharField(max_length=200) address = models.CharField(max_length=200) phone = models.CharField(max_length=15) driving_license = models.CharField(max_length=200) email = models.CharField(max_length=200) date = models.DateTimeField(default=datetime.now, blank=True) In the above function last line is showing too long and another warning related to Service class is also there. Here I need to remove both of the warning messages. Please help. -
Running Django function every n insert to a specific model
Is there a way to run a piece of code in Django when say 128 new entries are made to a specific model? -
how to use lampp server for django?
i want to use lampp localhost for hosting my django mywebsite. and to create database for website in lampp in django DATABASES = { 'default': { 'ENGINE': 'django.db.backends.mysql', #'NAME': os.path.join(BASE_DIR, ''), 'NAME': 'DB_NAME', 'USER': 'DB_USER', 'PASSWORD': 'DB_PASSWORD', 'HOST': '127.0.0.1', 'PORT': '3306', } -
Django Rest - Cant serialize items
I'm trying to serialize nested relations, but got an error during create model from request: 'MeasureUnit' object has no attribute 'unit' What am I doing wrong? I'm just trying to create model MeasureItem, but got error in MeasureUnit somehow. My models: from django.db import models from measure_unit.models import MeasureUnit from main_user.models import MainUser class Item(models.Model): code = models.CharField(unique=True, max_length=15) current_code = models.CharField(blank=True, null=True, max_length=15) title = models.CharField(default='', max_length=100) description = models.TextField(blank=True, null=True) measure_units = models.ManyToManyField(MeasureUnit, through='MeasureItem', through_fields=('item', 'unit'), blank=True) class Meta: ordering = ('created_at',) class MeasureItem(models.Model): item = models.ForeignKey(Item, on_delete=models.CASCADE, blank=True, null=True) unit = models.ForeignKey(MeasureUnit, on_delete=models.CASCADE, blank=True, null=True) quantity = models.IntegerField(default=0) created_at = models.DateTimeField(auto_now_add=True) updated_at = models.DateTimeField(auto_now=True) class Meta: ordering = ('created_at',) My serializer: from rest_framework import serializers from .models import Item, MeasureItem class MeasureUnitSerializer(serializers.ModelSerializer): class Meta: model = MeasureItem fields = ('id', 'unit') class ItemAdminSerializer(serializers.ModelSerializer): measure_units = MeasureUnitSerializer(many=True) class Meta: model = Item fields = ('id', 'code', 'current_code', 'title', 'description', 'measure_units') def create(self, validated_data): units_data = validated_data.pop('measure_units') item = Item.objects.create(**validated_data) for unit_data in units_data: try: measure_unit = unit_data['unit'] MeasureItem.objects.create(unit=measure_unit, item=item) except Exception as e: print(str(e)) return item return item -
clear input filed when clear button is pressed in Django
i have an input field in django html file and a clear button and i want to clear the input filed when the clear button is pressed. how can it be done? do i need to know javascript for that or it can be done otherway? <form> <input type="text" id="textfield1" size="5"> <input type="text" id="textfield2" size="5"> <input type="reset" value="Reset"> </form> i want to clear only one field not both -
Creating Inline formsets with many to many relationships
I have been learning django for a few weeks, Now I am trying to use inlineformset_factory to create related objects via foreign key, but I am having an error when creating the formset. These are my models: class Question(models.Model): content = models.TextField(max_length=1000,blank=False,verbose_name='Question') created_by = models.ForeignKey(User, on_delete=models.CASCADE,verbose_name="Author") created_date = models.DateTimeField(default=timezone.now) class Anwsers(models.Model): content = models.TextField(max_length=1000,blank=False,verbose_name='Answer') options = models.ManyToManyField(Anwsers,through='QuestionAnswers') class QuestionAnswers(models.Model): question = models.ForeignKey(Question) anwsers = models.ForeignKey(Anwsers) correct = models.BooleanField(blank=False,verbose_name="Correct") I tried to create the formset like this: AnwsersInlineFormSet = inlineformset_factory(QuestionAnswers,Anwsers.options.through) and this is the error I'm getting: ValueError: 'question.QuestionAnswers' has no ForeignKey to 'question.QuestionAnswers'. -
403 error with large media files
I'm running a Django server hosted on DigitalOcean using Nginx and Gunicorn. I tried adding a 2MB picture via the admin interface when I get hit with a 403 error. Looking into error.log indicated permission was denied, as follows: 2017/06/27 01:03:29 [error] 1643#1643: *30 open() "/home/brian/nydkc11/nydkc11/nydkcd11/media/image_main/dtc1.jpg" failed (13: Permission denied), client: 108.29.217.25, server: nydkc11.org, request: "GET /media/image_main/dtc1.jpg HTTP/1.1", host: "nydkc11.org", referrer: "http://nydkc11.org/admin/blog/image/7/change/" The weirdest thing, however, is that smaller image files work just fine (around 18 kb or so). Anyone know why larger media files may be triggering the problem, and how I should fix it? I had to set client_max_body_size to 100M in my nginx.conf, if that's a useful think to know. -
get_or_create returning error that multiple value of objects exist
I am trying to use get_or_create method to see if a record exists. If the record exists do nothing otherwise create it. This model is basically used on the command that is failing class modelStudentExamsPerformed(models.Model): patient = models.ForeignKey(modelPatient) student = models.ForeignKey(modelStudent,on_delete=models.CASCADE) normalBodyPart = models.ForeignKey(modelNormalBodyPartResult,default=None,blank=True,null=True) abnormalBodyPart = models.ForeignKey(modelAbnormalBodyPartResult,default=None,blank=True,null=True) tool = models.CharField(max_length=128, default="") Now this is the command that is using the above model and failing exams.modelStudentExamsPerformed.objects.get_or_create()(patient=patient_qset, student=stud_qset,abnormalBodyPart=qset[0],normalBodyPart=None,date=None) The above statement gives me the error : get() returned more than one modelStudentExamsPerformed -- it returned 2! Now this is where I am having trouble. When I look into the database through my admin I do notice two objects but those objects both have a value associated with normalBodyPart and their abnormalBodyPart is empty.Since I explicitly specified and assigned a value to abnormalBodyPart why does django say that two items already exist ? I hope this makes sense . Let e explain this another way as well suppose there are two statements 1 and 2. Statement 1 gets or creates a record based on a specified parameter . This get or create fails as django thinks there are already two records. However statement 2 uses the same exact parameters and returns 0 records. ... -
How to transform this rules into code in python?
I would like some HELP!! I want to make a simple noob function before put into my django project. I want a function that provides the lamp power of a room. Input: The room's area (m²) Output: The lamp power (W). The rules of this math is: If the entry area is <= 6m² then the power will be 100W (easy). If the area is > 6m² then for the first 6m² the power is 100W, BUT for the next 4m² is added 60W to the lamp power. Ex: Area = 20m² 6m² + 4m² + 4m² + 4m² + 2m² = 20 m² 100 + 60 + 60 + 60 + 0** = 280 W **(less than exact 4m² doesn't count) def light(area): power = 0 if area < 6: power = 100 else: ........ return power print(light(20)) Any help to make this simple code would be AWESOME! -
Performance issues with weave networking on Kubernetes cluster
I create a Kubernetes (v1.6.1) cluster on AWS with one master and two slave nodes, then I spin up mysql instance using helm and deploy a simple Django web-app that queries latest five rows from the database and displays it. For my web service I specify 'type: LoadBalancer' which creates an ELB on AWS. If I use 'weave' networking and scale my web-app to at least two replicas, then I begin experiencing inconsistent response time - most of the time it is reasonable (like 0.1-0.2 s), but 20-40% requests take significantly longer (3-5 s, sometimes even more than 15 s). However, if I switch to 'flannel' networking, everything works fast, even with 20-30 replicas of the web-app. All machines have enough resources, so that's not the problem. I tried debugging to find out what's causing the delay, and the best explanation I have is that AWS ELB doesn't work well with 'weave'. Has anyone experienced similar issues? What could be the problem? Please let me know if I should provide some relevant information. P.S. I'm new to using Kubernetes. -
django - Filter items list
I have a web page made with Django thats show albums of music. I want to add filters in order to show albums that have special singer for example and add a boutton to sort by name. -
Django 1.6, all() throws error: Cannot set values on a ManyToManyField which specifies an intermediary model
I am having an exception in Django 1.6 with Python 2.7.13 (x86), and I don't know to to fix this. I already searched other posts for the answer, but to no avail. I am stuck on this, and have been spinning my wheels for a while. This is the line of code that throws the exception: myNewClass.class_students = selectedClass.class_students.all() Please see the complete code example below... This is the error message that I am getting: Cannot set values on a ManyToManyField which specifies an intermediary model. Use MyApp.ClassStudents's Manager instead. (For the above error message, my app is called 'MyApp'...) It seems like all() does not work, is there anyway to fix this? Can you guys please help me fix this or at least point me in the right direction... Thanks. Here is my code: class Class(models.Model): courseNumber = models.IntegerField() courseName = models.CharField(max_length = 32) class_students = models.ManyToManyField(Student, blank = True, through = 'ClassStudent') class Student(models.Model): studentName = models.CharField(max_length = 32) overallStudentGPA = models.IntegerField() class ClassStudent(models.Model): myClass = models.ForeignKey(Class, on_delete = models.CASCADE) myStudent = models.ForeignKey(Student, on_delete = models.CASCADE) studentClassGrade = models.IntegerField() def copy_class(modeladmin, request, queryset): for selectedClass in queryset: myNewClass = Class(courseNumber = selectedClass.courseNumber, courseName = selectedClass.courseName) myNewClass.courseNumber = selectedClass.courseNumber ... -
How to get the values of a request in Python?
I get this result when I print the request, which arrived at a POST. <QueryDict: {u'form_values': [u'nombre=Juan&apellidos=Perez&correo=juan@email.com&confiCorreo=juan@email.com&telefono=5598764&celular=8971265256&calle_numero=Calle+#10&colonia=San+Pablo&municipio=&estado=&pais=&cPostal=&razonS=&rfc=&callenumero=&colonia=&municipio=&estado=&codPos='], u'pass': [u'k7iwriilqm66mtnu2m1x'], u'csrfmiddlewaretoken': [u'kkxdVbDzPXhfDazzSVvIvAYizExoRSFR'], u'clabe': [u'8jO9ChGsKXJfrBtb4vBMsxQKdA8L7Y0h']}> How can I get the values that come from form_values individually (nombre, apellidos)? -
Declaring a Django signal inside a method
I'm trying to remove a file that I've created after it's been sent to the user: def download_file(request, contents): f = NamedTemporaryFile(delete=False) def test_signal(sender, **kwargs): print 'finished' os.remove(f.name) request_finished.connect(test_signal) f.write(contents) f.close() response = HttpResponse(FileWrapper(open(f.name)), content_type='application/force-download') response['Content-Disposition'] = 'attachment; filename=%s' % smart_str('file.txt') return response Downloading the file works fine, but the signal won't get triggered. What puzzles me is that it does work when I put test_signal() outside of the download_file(), i.e. declaring it above at the same level, but if I do that I can't access the name of the file to remove. Why can't I use test_signal() when it's declared inside this method? -
Django: TypeError: context must be a dict rather than str
I wanto to redirect to an url if the object of GroupMember doesn't exist but shows this error: TypeError: context must be a dict rather than str. Here is my view: class GroupDetail(DetailView): template_name = "group_detail.html" model = Group def get_context_data(self, **kwargs): context = super(GroupDetail, self).get_context_data(**kwargs) # Code try: group_member = GroupMember.objects.get(member=volunteer, group=group) context['group_member'] = group_member # Code return context except: return reverse('users:home') I try with redirect and reverse_lazy but shows the same error an try with reverse('users:home', {}), reverse('users:home', kwargs={}) and reverse('users:home', kwargs=None) -
Firebase message not received by browser
I have a Django project in which I use Firebase cloud messaging to power up push notifications. Here is my code: index.html <script> var config = { // ... }; firebase.initializeApp(config); const messaging = firebase.messaging(); navigator.serviceWorker.register('/static/firebase-messaging-sw.js').then((registration) => { messaging.useServiceWorker(registration); messaging.requestPermission().then(function() { console.log('Notification permission granted.'); return messaging.getToken(); }).then(function(token){ $.post('/a_send_fcm_token/', {'fcm_token_web': token}); }).catch(function(err){ console.log('Error ocurred'); }); }); messaging.onMessage(function(payload) { console.log('Hoorah'); // does not work :( }); </script> Because Django project layout has certain peculiarities, I use navigator.serviceWorker.register() function in the above code to change the default location of firebase-messaging-sw.js file which would otherwise be in the root directory of the project. My firebase-messaging-sw.js looks like this: importScripts('https://www.gstatic.com/firebasejs/4.1.2/firebase-app.js'); importScripts('https://www.gstatic.com/firebasejs/4.1.2/firebase-messaging.js'); var config = { apiKey: "AIzaSyCvt-sddXFg7Kjrttu42O6nagQIbo58bbY", authDomain: "android-blend-4b456.firebaseapp.com", databaseURL: "https://android-blend-4b456.firebaseio.com", projectId: "android-blend-4b456", storageBucket: "android-blend-4b456.appspot.com", messagingSenderId: "1024370094646" }; firebase.initializeApp(config); const messaging = firebase.messaging(); And finally, my Django view which posts message to FCM: headers = {'Authorization': "key=AAAA7oE3MjY:APA91bE_M-BtgujBl2p5s2NQ2WPjseWx7c6CET5s-xMcbCzxWYm7Odk-FOPN9RDVi-_3vozaSZeWUaj02vWe_3GDSWyHU8qozODhfxSohbR5hi7thBO3gjWEdnZKnABggKL8pat7IDSr"} user_web_tokens = UserWebTokens.objects.filter(user = request.user)[0].token payload = {"data": {}, "to": user_web_tokens} r = requests.post("https://fcm.googleapis.com/fcm/send", data=payload, headers=headers) return True It seems like I've implemented most of the stuff correctly because I succeed in obtaining token from FCM. But I can't make FCM to the message to me, so: The question: Why doesn't my messaging.onMessage() work ? -
Indexing and searching related objects with haystack
I'm pretty new to search implementation, bear with me while I'm learning! So my pet project is a recipe site and each recipe can have n steps. the model looks something like: class Recipe(models.Model): title = models.CharField(max_length=255) description = models.TextField() hotness = models.ForeignKey(Hotness) recipe_diet = models.ManyToManyField(DietType) ingredients = models.ManyToManyField(Ingredient, through="RecipeIngredient") class DietType(models.Model): diet_type = models.CharField(max_length=50) description = models.TextField(null=True, blank=True) class RecipeIngredient(models.Model): recipe = models.ForeignKey(Recipe) ingredient = models.ForeignKey(Ingredient) quantifier = models.ForeignKey(Quantifier) quantity = models.FloatField() class RecipeSteps(models.Model): step_number = models.IntegerField() description = models.TextField() recipe = models.ForeignKey(Recipe) (shortened for brevity) I want to index all of it: Recipe, RecipeIngredient, DietType and Steps... The DietType and RecipeIngredient seem to be working fine, but the Steps are not. I assume this has to do with the usage of 'RelatedSearchQuerySet' ? Here is my search_indexes.py: from haystack import indexes from recipes.models import Recipe class RecipeIndex(indexes.SearchIndex, indexes.Indexable): text = indexes.CharField(document=True, use_template=True) title = indexes.CharField(model_attr='title') ingredients = indexes.MultiValueField(indexed=True, stored=True) description = indexes.CharField(model_attr='description') hotness = indexes.CharField(model_attr='hotness') diet_type = indexes.MultiValueField(indexed=True, stored=True) recipesteps = indexes.MultiValueField(indexed=True, stored=True) def prepare_steps(self, object): return [step.description for step in object.recipesteps.all()] def get_model(self): return Recipe def load_all_queryset(self): # Pull all objects related to the Note in search results. return Recipe.objects.all().select_related() Here is the template recipe_text.txt: {{ object.title ... -
What is the most efficient way to create models for storing tags in Django 1.9 and Postgres 9.5?
I want to make a model where I have the option of pulling a group of items and their descriptions from a postgres database based on tags. What is the most efficient way of doing this for performance using Django 1.9 and Postgres 9.5? I found multiple ways of doing this: Toxi solution Where 3 tables are made, one storing the item and descriptions, second storing the tags, and a third table associating tags with items. See here: What is the most efficient way to store tags in a database? Using Array fields Where there is one table with items, descriptions, and an array field that stores tags Using JSON fields Where there is one table with items, descriptions, and an JSON field that stores tags. The django docs mention this uses JSONB: https://docs.djangoproject.com/en/1.11/ref/contrib/postgres/fields/ I am guessing that using JSON fields like the following: from django.contrib.postgres.fields import JSONField from django.db import models class Item(models.Model): name = models.CharField() description = models.TextField(blank=True, null=True) tags = JSONField() is the most efficient but I am not really sure. -
Django form how to show logged in user only?
I have a django model "Post" that has a field: author = models.ForeignKey('auth.User') I also have a PostForm in forms.py with author as a field and Post as the model. I want to only show the user logged in and not all superusers. https://gyazo.com/fb8884391bdf8284065175fbcdc16f75 Is there a painless way of doing so? If not what is my best option? -
Django nested query PostgreSQL
class Route(app_core_base_model.AbstractDefaultModel): code = models.PositiveIntegerField( verbose_name=_('code'), default=0, editable=True) slug = models.SlugField( verbose_name=_('slug'), unique=True, max_length=255, blank=True, null=True, editable=True, db_index=True) class Route(app_core_base_model.AbstractDefaultModel): code = models.PositiveIntegerField( verbose_name=_('code'), default=0, editable=True) slug = models.SlugField( verbose_name=_('slug'), unique=True, max_length=255, blank=True, null=True, editable=True, db_index=True) class StopPoint(app_core_base_model.AbstractDefaultModel): route = models.ForeignKey( Route, verbose_name=_('route')) station = models.ForeignKey( app_core_models.Station, verbose_name=_('station')) arrival_time = models.TimeField( verbose_name=_('arrival time'), blank=True, null=True, editable=True) departure_time = models.TimeField( verbose_name=_('departure time'), blank=True, null=True, editable=True) class Station(app_core_base_model.AbstractDefaultModel): name = models.CharField( verbose_name=_('name station'), max_length=255, blank=True, null=True, editable=True) slug = models.SlugField( verbose_name=_('slug'), unique=True, max_length=255, blank=True, null=True, editable=True, db_index=True) I have 3 models I can not make a request that will be able to choose all flights that pass through the point of arrival and the point of departure. How can I find all routes that are passing through and the point of departure to the arrival point? -
Django: Cannot set values on a ManyToManyField which specifies an intermediary model
I have a problem with a CreateView in my Django app, I want to create a Sesion but the sessions can only be created by a GroupMember leader of that Group. Here are my models: class Group(models.Model): # The code class GroupMember(models.Model): member = models.ForeignKey(Volunteer) group = models.ForeignKey(Group) leader = models.BooleanField(default=False) class Session(models.Model): name = models.CharField(max_length=250) group = models.ForeignKey(Group) assistants = models.ManyToManyField(GroupMember, through='SessionAssistant') hours = models.FloatField(default=1) day = models.DateTimeField(default=datetime.now) class SessionAssistant(models.Model): assistant = models.ForeignKey(GroupMember) session = models.ForeignKey(Session) rol = models.CharField(max_length=250) assist = models.BooleanField(default=True) Also I want when I create a Sesision I can assign de rols of my assistants, here is my view: class CreateSession(CreateView): model = Session template_name = "session_form.html" fields = ['name', 'hours', 'day', 'assistants', ] success_url = '/' def form_valid(self, form): group = Group.objects.get(id=self.kwargs['pk']) form.instance.group = group return super(CreateSession, self).form_valid(form) -
Iterating models fields and updating them in Django
I have a model named UserInfo. class UserInfo(models.Model): username = models.CharField(max_length=240 , default = "" , blank = False , null = False) first_name = models.CharField(max_length=240 , default = "" , blank = False , null = False) last_name = models.CharField(max_length=240 , default="" , blank = False , null = False) address = models.CharField(max_length=500 , default="" , blank = False , null = False) email = models.CharField(max_length=240 , default="" , blank = False , null = False) phoneNumber = models.CharField(max_length=240 , default="" , blank = False , null = False) pincode = models.CharField(max_length=240 , default="" , blank = False , null = False) I also have a UserInfoFormthat has these fields. class UserInfoForm(forms.ModelForm): class Meta: model = UserInfo fields = [] for field in UserInfo._meta.get_fields(): #automatically update fields from userinfo model fields.append(field.name) exclude = ['username'] What is want is to iterate over the fields of UserInfo model and update with data in UserInfoForm, rather than hardcoding it all. I have tried this: obj = UserInfo.objects.get(email = request.user.email) if obj.username == request.user.username: #basically a test to see if the same person is updating his profile, or is someone else using this email id for field in UserInfo._meta.get_fields(): fieldname = field.name fieldvalue ... -
DateField in Django missing Hours, Minutes, Seconds
I have a Date field in an oracle 12c legacy table which has data like 18-JAN-14 12 34 59. In my django 1.10 app I have a corresponding model with a field time = models.DateField(blank=True, null=True). The problem is when I examine an instance of the model I get something like datetime.date(2014, 1, 18)....what happened to the hours, minutes, and seconds? Thanks! -
when i use object name i get 'DeferredAttribute' object has no attribute 'get'
i'm new for django. i'm really confused with views filters. this is my models.py class Author(models.Model): title = models.CharField(max_length=30) user=models.ForeignKey(User) age= models.CharField(max_length=2) post= models.ManyToManyField(Article) def __str__(self): return self.title def __str__(self): return self.post def __str__(self): return self.age class Meta: ordering = ('title','user',) my views.py def posting(request): details = Author.age.get(pk=request.user.id) return render(request,'home.html' , {'detail':details}) Now i need to get the current logged in user (age or title or post).when i execute the code i get the above error. how can i filter the particular object of logged in user kindly suggest me some docs for views filter Thanks for advance !!
