Django community: Django Q&A RSS
This page, updated regularly, aggregates Django Q&A from the Django community.
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api design concept using django rest framework
My question or say my confusion is Does api design depends on how we present in UI? I will illustrate my confusion with one of an example. Will the api design be different if i want the form to be in multiple step? I mean in the https://www.franchisebazar.com/franchisor-registration if you see the form for company registration, there are section like company information, company brand and business model which are associated with company model. The submit button is only one that means there will be only one api for posting the company data. But what if I want the UI be different(multiple steps wizard form instead of one single big form) like company info in the first step and after submitting company personal info, the next step will be brand and then business model at last. For this do i need to design an api separately? One for company personal info, one for brand and one for business model. up to now my design is following https://gist.github.com/MilanRgm/132eb6c0ba0cf66e48fa0ca4c17ef732 I will brief it in the list again 1) API design for registering company profile using one single big form 2) API design for registering company profile using multiple step way I am confused ... -
Python Module 'Requests' and 'Messages Framework'
within a Django web app, I am using the aforementioned modules: Requests to handle HTTP and Messages Framework to collect and render messages Now, when I am calling the following method of the Messages Framework: messages.add_message(request, messages.INFO, 'Hello world.') it gives me an error saying it requires an HTTPRequest... however, 'Requests' does not match. Any ideas? The full error message is: add_message() argument must be an HttpRequest object, not 'module'. The preceding method call for a post is: import requests <some code...> response = requests.post(url=dest, data=self.settings, headers=headers) -
how to resolve pagination for queries, and result to "None", on Django?
I've been trying to solve this for hours, I already looked in the doc, in stackoverflow, but no way it worked so far. I have two problems. I need to put in the title "no results found" if no results are found, or if the person enters the search url directly, without providing anything to search. I need to create a paging link, but it does contain the result of the query. I've already tried href = href="search?q={{ query }}?page={{page.next_page_number}}" But the query passed by the view does not appear on the link, which results in "search? Page = 2". As for the first problem, I have tried <h1 class="title is-5"> {% if posts.paginator.count > 0 %} {{ posts.paginator.count }} Resultado{{ posts.paginator.count|pluralize }} para "{{ query|truncatechars:30 }}" {% else %} Nenhum resultado encontrado {% endif %} </h1> Remembering that I am a beginner and I do not know how to speak English, I am trying to become an online translator and google. -
Get column values from MongoDB table to Django
How should I create a model.py when I already have an existing mongoDB database. I only want to get the values from an existing Table to a the HttpResponse in Django views.py. Is there any reference material for me to go over this? -
Django - create dictionary of associated objects
I'm attempting to build a query which will return a list of all technologies and the users score associated with each. This is based on the following models: class technology(models.Model): technology = models.CharField(max_length=64) class result(models.Model): user = models.ForeignKey(User, on_delete=models.CASCADE) technology = models.ForeignKey(technology, on_delete=models.CASCADE) skill_level = models.ForeignKey(skill, to_field='level', on_delete=models.CASCADE) class skill(models.Model): level = models.IntegerField(unique=True) Essentially I'd like to see somthing similar to the following: {technology: Cisco, users: {Alex: {skill_level: 1}}, {James: {skill_level: 2}} I'm not sure whether this can be acheived with a simple query or whether custom joins will need to be done? I'm also not sure whether I should be building this on the technology model or the result model? -
How to debug Django on docker while using eclipse on windows.
My objective is to debug my django application in my window's eclipse while it is running on docker (no sure if it is doable). My test here is to see if the code is on nt (windows) or not by: import os print ("your OS is: "+os.name) For this test I don't want to see "nt" (windows) but rather the docker container OS (ubuntu). What confuses me here is how does docker's container associate the code I have to the container? In other words, if I make a change in the code on eclipse, how does the container "web" knows about it? I realized that the volume is where I should define the path but didn't quite understood how to do it properly. What I did is this (and I'm a docker newbie): Under my directory of eclipse where my djangoPrj is located I have the docker-compose file such that: version: '2' volumes: postgis-data: services: web: build: context: . dockerfile: Dockerfile.debug ports: - "8000:8000" volumes: - .:/djangoPrj links: - db db: image: kartoza/postgis:10.0-2.4 volumes: - 'postgis-data:/var/lib/postgresql' environment: - POSTGRES_DB=tankers_db - POSTGRES_USER=userABC - POSTGRES_PASS=passwordABC - ALLOW_IP_RANGE=0.0.0.0/0 ports: - 5432:5432 restart: unless-stopped my Dockerfile.debug is (not sure the last line is necessary): ... -
How to make the fields read only in django admin except for the superuser?
I have the following model defined: class PRegistration(models.Model): user = models.ForeignKey(User, on_delete=models.CASCADE, null=True, blank=True) create_date = models.DateTimeField(auto_now=False, auto_now_add=True) teamName = models.CharField(max_length=144) city = models.CharField(max_length=144) How do I make all these fields read only in the admin page for all staff accounts except the superuser? I wanna do this without specifying the fields one by one so that I can reuse the code in multiple places. -
Models with optional fields with relations
I am looking for a clean way to model data that is optional, but if included will contain a reference to other data. In example below, the cleanest relational modeling is to separate person, insurance plan, and insurance company. class InsurancePlan(models.Model): name = models.CharField(max_length=100, default="Not Indicated") insurancecompany = models.ForeignKey(InsuranceCompany, on_delete=models.CASCADE, null=True, blank=True) claims_address = models.OneToOneField(UsLocation, on_delete=models.CASCADE, blank=True, null=True) class InsuranceCompany(models.Model): name = models.CharField(max_length=50) some_important_id = models.CharField(max_length=50) class Insured(models.Model): name = models.CharField(max_length=50) plan = models.ForeignKey(InsurancePlan, on_delete=models.CASCADE) and then either add a "member_id" field to the insured model or create an Insured_Plan table that links them. However, what if the business requirements say that having InsurancePlan information is optional, because we can get by just knowing member ID and InsuranceCompany? is it ok to have: class Insured(models.Model): name=... plan = models.ForeignKey(InsurancePlan, on_delete=models.CASCADE, null=True, blank=True) insurance_summary = models.ForeignKey(InsuranceCompany, on_delete=models.CASCADE) member_id = models.CharField() Im a bit rusty on relational modeling, but I think having a fk from A to B, and another from A to C where C has a fk to B as well is not good practice. -
How to get an instance from a serializer in Django
I'm trying to get an instance from own serializer def perform_create(self, serializer): serializer.save(slug=utils.unique_slug_generator(**serializer.validated_data),user_profile=self.request.user) but didn't work because in unique_slug_generator i try to access to title of instance ModelClass = instance.__class__ qs_exists = ModelClass.objects.filter(slug=slug).exists() Error : unique_slug_generator() got an unexpected keyword argument 'title' -
Django : I am going to make the system with clients and employees via REST Framework in Custom Admin Panel
I am going to make Admin Panel based on Angular JS. And, this Admin panel will be used by certain Admin, and other users can't access this admin panel. Also, in this panel, we have to manage all users with several roles. How to configure the structure of this project? Please give me the advice. -
Printing in EPSON EPSON TM U220D Model M188D
I want to print a ticket from my printer Printing in EPSON EPSON TM U220D Model M188D but using the python-escpos library does not work for me. What is the error? def imprimir_ticket(): from escpos.printer import Usb p = Usb(0x04b8, 0x0202, 0, profile="TM-U220") p.text("Hello World") p.cut() -
Accessing last row from table C that has FK from table B, which is in one-to-one relationship with A
Let's say we have 3 models: class A(models.model): name = models.CharField(max_length=30, unique=True) class B(models.model): name = models.CharField(max_length=30, unique=True) a = models.OneToOneField(A, on_delete=models.CASCADE, primary_key=True) class C(models.model): name = models.CharField(max_length=30, unique=True) b = models.ForeingKey(B, on_delete=models.CASCADE) transaction_count = models.IntegerField(default=0) and one view: class AListView(generic.ListView): model = A In that view (template) I need to show: name of A, name of B and the last row (ordered by date) of "transactioncount" for each repository from b. In my template I iterate over items in A and show them in following way: {% for a in A %} <tr> <td>{{a.name}}</td> <td>{{a.b.name}}</td> <td>{{??? Don't know what to put here, to show the last row. I tried: a.b.c|last}}</td> </tr> {% endfor %} I tried to build custom tags and use template functions like, but that unfortunately doesn't work: {% with a.b.c_set.all|last as val %} <td>val</td> {% endwith} Among my other tries would be to build a new queryset, but then I don't know how to assign items from model A to that queryset. I tried: def get_context_data(self, **kwargs): context = super().get_context_data(**kwargs) context.update({ 'A': A.objects.all(), 'c_data': C.objects.order_by('B', '-date').distinct( 'B') }) ) What would be the best "pythonic" way to do this? Thanks -
How convert string to a datetime object to be stored and rendered correctly in Django & PostgreSQL?
I'm facing a strange behaviour when trying to convert a string which contains a date then convert it to a datetime object then store it in my PostgreSQL database to be rendered it in Django template. Let's take this example: I have a string like this one: string_date = '15/09/2018 20:30' I know the timezone of this string date which is Europe/Paris So i created a function to convert this string date into an aware datetime object: import pytz from datetime import datetime def create_aware(date): naive = datetime.strptime(date, '%d/%m/%Y %H:%M') # is_dst = True, because Paris is in DST regions # At least this what i've found while searching ... localized = pytz.timezone('Europe/Paris').localize(naive, is_dst=True) return localized Also, i know that Django stores dates within UTC timezone into PostgreSQL. So, basicaly all the dates stored will be normalized to UTC timezone. In my settings.py i use: TIME_ZONE = 'Africa/Tunis' USE_TZ = True But, the problem comes in the backend and while rendering the dates in the template. For this particular date, in the Admin panel it's rendered as: 15/09/2018 2018 20:49 which is incorrect. Because my local timezone Africa/Tunis is ahead by 1 hour from Europe/Paris timezone. And in the template: ... -
Django; how to load static files that are created by ManifestFileMixin
I'm trying to use ManifestFileMixin for cache busting in Django project. I was successful in uploading the static files on S3. But seems like the files are not loaded on html. Old files are still loaded. How can I fix this? I tried to use replace <script src="{% static 'js/file.js' %}></script> with @import url("js/file.js") but it still doesn't work. The purpose of using ManifestFileMixin is because I want to load new static files immediately after I update the files on S3. The changes cannot be reflected on html unless the users clean the browser cache. Is there a way to reflect changes on s3 quickly? -
Do custom template tags cause a database query?
I am using 5 - 6 custom template tags. Each one of them is similar to the following: @register.filter(name = 'time_left') def time_left(obj): if not obj: return -1 if not obj.has_offer_expired(): return obj.time_left() return None I have this in my models.py: def has_offer_expired(self): return self.end_time <= timezone.now() def time_left(self): return int((self.end_time - timezone.now()).total_seconds()) Whenever the template tag is used, {{ offer | time_left }}, will it cause a database query? Or, offer is passed to the template tag function and its attributes are used without causing any extra db query? A detailed explanation of the working of template tags behind the scenes would be much appreciated! Thank you. -
How can I not save child models to parents at ForeignKey?
There are two models of Factory and Pipeline. When creating objects, they are passed over the websocket to the client. Due to the fact that the ScenarioExist and PipelineTwo models are associated with Factory and Pipeline, they are also immediately transferred to the client. Is it possible to make sure that the objects created in ScenarioExist and PipelineTwo are not redirected to the client, but they belong to Scenario? models.py(Scenario, ScenarioExist, PipelineTwo) class Scenario(models.Model): title = models.CharField(max_length=200) class ScenarioExist(models.Model): scenario = models.ForeignKey('Scenario', related_name='scenario_exist', on_delete=models.CASCADE) factory = models.ForeignKey(Factory, related_name='factory', on_delete=models.CASCADE) class PipelineTwo(models.Model): scenario = models.ForeignKey('Scenario', related_name='scenario_pipeline', on_delete=models.CASCADE) pipeline = models.ForeignKey(Pipeline, null=True, on_delete=models.CASCADE, related_name='point_two') models.py(Factory) class Factory(models.Model): OBJECT_CHOICES = ( ('Factory', 'Завод'), ('Sump', 'Вышка'), ('Storage', 'Хранилище'), ('Petrol', 'АЗС') ) title = models.CharField(max_length=200) choice = models.CharField(max_length=15, choices=OBJECT_CHOICES, default='') address = YmapCoord(max_length=200, start_query=u'Россия', size_width=500, size_height=500, unique=True) Pipeline is about the same -
How to render json data from a function?
I am using a tutorial on Django sessions, where there is a function written to delete session on logout url call, but i want to use Ajax to call that function but problem is ajax giving error as im returning HttpResponse instead of any json response so can i know how to convert this function to render some json response? views.py def logout(request): try: del request.session['username'] except: pass return HttpResponse("<strong>You are logged out.</strong>") url.py url(r'^logout/', 'logout', name = 'logout') -
Celery periodic task not accessing module variables
I have a celery well configured and working with django. On post_save signal, I send a new record to a set using a task and using another periodic task, I m trying to consume that set. from __future__ import absolute_import, unicode_literals from celery import shared_task class Data(): def __init__(self): self.slotshandler = set() global data data = Data() @shared_task def ProcessMailSending(): #This is a periodic task, running every 30 seconds global data #This variable is always empty here while slotshandler: slot_instance = slotshandler.pop() print("sending mail for slot } to {} by mail {}".format(slot_instance .id,slot_instance .user,slot_instance .user_mail)) @shared_task def UpdateSlotHandler(new_slot): #This is called by save_post django signal global data data.slotshandler.add(new_slot) #filling the set at each new record The problem is that this task doesn't see my newly added time slots. note that this django app is run on a micro service for sending reminder mails to users. -
upload django site to the web hosting service
Hello im about the finish my first ever django website and I dont know how to upload it to the internet Bcuz I want to buy a web hosting service and to run django server I need to run a command python manage.py runserver and how is the web hosting service gonna do it? how should I upload my django website? -
Django; ManifestFilesMixin doesn't overwrite the old static files
I was trying to use ManifestFilesMixin for cache busting. But it doesn't overwrite the old files and create a bunch of static files. Is this default? How can I fix this? storage_backends.py is like this class StaticStorage(ManifestFilesMixin, S3Boto3Storage): location = settings.STATICFILES_LOCATION But this error happened so I tried like this as one of the answers on the issue. class CustomS3Boto3Storage(ManifestFilesMixin, S3Boto3Storage): def _save_content(self, obj, content, parameters): content.seek(0, os.SEEK_SET) content_autoclose = SpooledTemporaryFile() content_autoclose.write(content.read()) super(CustomS3Boto3Storage, self)._save_content(obj, content_autoclose, parameters) if not content_autoclose.closed: content_autoclose.close() class StaticStorage(CustomS3Boto3Storage): location = settings.STATICFILES_LOCATION It fixed the error but the static files cannot be overwritten. -
Read information about a directory and it's sub-directories using python
I'm working on a python(3.6) project in which I need to clone a GitHub repo which will have the directory structure as: |parent_DIR |--sub_DIR |file1.... |file2.... |--sub_DIR2 |file1... Now I need to get the following info: 1. Parent directory name 2. How many subdirectories are 3. names of subdirectories Here's how I'm cloning the GitHub repo: from views.py: # clone the github repo tempdir = tempfile.mkdtemp() saved_unmask = os.umask(0o077) out_dir = os.path.join(tempdir) Repo.clone_from(data['repo_url'], out_dir) -
Ingress and Ingress controller how to use them with NodePort Services?
I have a single service running on a NodePort service. How do i use ingress to access multiple services. deployment.yml apiVersion: apps/v1 kind: Deployment metadata: name: auth spec: replicas: 1 selector: matchLabels: app: auth template: metadata: labels: app: auth tier: backend track: dev spec: containers: - name: auth image: [url]/auth_app:v2 ports: - name: auth containerPort: 3000 service.yml apiVersion: v1 kind: Service metadata: name: auth spec: selector: app: auth tier: backend ports: - protocol: TCP port: 3000 targetPort: auth type: NodePort ingress.yml apiVersion: extensions/v1beta1 kind: Ingress metadata: name: test-ingress spec: backend: serviceName: auth servicePort: 8080 I followed step by step from the this repo. I could not get it working for my port config. I'm a beginner and would like some resources for the same. -
Django - retrieve url from HttpResponse object?
In Django test cases, how do you get the url from a HttpResponse object? If I have the following Django app: urls.py from django.urls import path from . import views urlpatterns = [ path('httpresponse/', views.http_response, name='http_response'), ] views.py from django.shortcuts import render def http_response(request): return render(request, template_name='home.html') tests.py from django.test import TestCase from django.urls import reverse http_response = reverse('http_response') class TestTemplateResponse(TestCase): def test_http_response(self): response = self.client.get(http_response) self.assertEqual(response.url, http_response) The unit test fails with the following message: AttributeError: 'HttpResponse' object has no attribute 'url'. Is there any way to get the client to return a Response object, instead of HttpResponse? -
Django - TypeError: expected str, bytes or os.PathLike object, not NoneType
i am having a problem when i run any manage.py command it show me this error -
In Django, unable to use related_name to fetch username from User class
class Topic(models.Model): subject = models.CharField(max_length=255) last_updated = models.DateTimeField(auto_now_add=True) board = models.ForeignKey(Board, on_delete = models.CASCADE, related_name='topics') starter = models.ForeignKey(User, on_delete = models.CASCADE, related_name='topics') views = models.PositiveIntegerField(default=0) I need to get the starter full name in a query. I have written the following query in shell and it is giving an error print(Topic.objects.all().values('board__description','subject','user__username')) The error is : Cannot resolve keyword 'user' into field. Please could you help and thanks in advance.
