We Keep Coding

Python django model object showing None and null in template

I have this table.
class MyTable(BaseModel):
key = m.CharField(max_length=20,null=False,unique=True)
pre_json = m.JSONField(blank=True, null=True)
post_json = m.JSONField(blank=True, null=True)
And I use this model through ListView/UpdateView
list view is here.
class MyTableListView(LoginRequiredMixin, ListSearchView):
model = MyTable
form_class = MyTableForm
template_name = 'mytable_list.html'
class MyTableForm(forms.ModelForm):
key = forms.CharField(required=True)
pre_json = forms.JSONField
post_json = forms.JSONField
class Meta:
model = sm.ScenarioWorker
fields = ["key","key","pre_json","post_json"]
in list html template
{{obj.pre_json}}
in edit html template
{% render_field form.pre_json class="form-control" %}
Upper one shows None in template
Lower one shows null in textarea as placeholder.
Why this two are shown? or can I erase these?
I want to stop this.

Sum Foreignkey objects to loop

I'm trying create a table with 2 columns:
1) Collections and 2) Qualified Sales.
Like the image above.
Each book count the own qualified_sales.
The Qualified sales(column in the table) must sum all qualified_sales of all books of each collection.
models.py
class Publishing_company(models.Model):
title = models.CharField(max_length=50)
class Collection(models.Model):
publishing_company = models.ForeignKey(Publishing_company, on_delete=models.CASCADE)
class Book(models.Model):
publishing_company = models.ForeignKey(Publishing_company, on_delete=models.CASCADE)
class Sale(models.Model):
book = models.ForeignKey(Book, on_delete=models.CASCADE)
qualified_sale = models.IntegerField(default=0)
views.py
def qlf_sales(request):
book = Collection.objects.filter(user=request.user)
qualified_sum = Sale.objects.filter(user=request.user, book__publishing_company__collection__in=book).aggregate(Sum('qualified_sale'))['qualified_sale__sum'] or 0
context = {'qualified_sum': qualified_sum}
return render(request, 'template.html', context)
template.html
{% for collection in collections %}
<tr>
<td>{{collection}}</td>
<td>{{qualified_sum}}%</td>
</tr>
{% endfor %}
But this code not work. Dont appear any debug error, but in the all fields in the Qualified Sales' column appear the same value: the sum of all qualified_sales of all sales of all book.
why didn't separate by collection?
If anyone can help me. Please i go a lot grateful.

Showing Many-To-Many in different model's form in Django?

Say I have three models, a Professor model, a Course model, and a Review model. The user is allowed to make a Review, which reviews a Professor that teaches a certain Course.
I'm thinking of how to model the many to many relationship of Professor and Course, and how to reference that relationship in Review. My idea so far is to use models.ManyToMany to link Professor and Course.
Models.py (Prof)
class Prof(models.Model):
first_name = models.CharField(max_length = 20, unique = False)
last_name = models.CharField(max_length = 20, unique = False)
def __str__ (self):
return self.first_name + " " + self.last_name
class Course(models.Model):
name = models.CharField(max_length = 20, unique = True)
prof = models.ManyToManyField(Prof)
def __str__ (self):
return self.name
Models.py (Review)
class Review(models.Model):
message = models.TextField(max_length = 4000)
created_at = models.DateTimeField(auto_now_add = True)
updated_at = models.DateTimeField(null = True)
rating = models.IntegerField(
default = 5,
validators = [MaxValueValidator(5), MinValueValidator(0)]
)
prof = models.ForeignKey(Prof, related_name = 'reviews')
course = models.ForeignKey(Course, related_name = 'reviews')
user = models.ForeignKey(User, related_name = 'reviews')
def __str__ (self):
return self.message
forms.py
class ReviewForm(ModelForm):
rating = CharField(widget=TextInput(attrs={'type': 'number','value': 5, 'min': 0, 'max': 5}))
class Meta:
model = Review
fields = ['message', 'rating', 'prof', 'course', 'user']
This is my code so far for displaying the form
<h1>New Review</h1>
<form method="POST">
{% csrf_token %}
<p>{{ review_form.message }}</p>
<p>{{ review_form.rating }}</p>
<p>{{ review_form.prof }}</p>
<!-- The prof chosen's courses should be shown here -->
<button type="submit">Save</button>
</form>
Right now, forms.py shows all the objects under Course, and i'm not sure how to instead show the courses of a professor. Is it possible to filter the form after a prof is chosen from the drop down, to display the courses he/she teacher?

It sounds like you're going about this the right way. You haven't mentioned your urls.py structure yet, or views.py but the most straightforward way to do this is to display the courses by professor, taking the professor's id (or slug-field) in as a parameter - either in the URL (v straightforward) or as the output from a form on a previous page (and reload the template with a professor parameter) or in Ajax, depending on your appetite for shiny-new-things.
In your view, when you call the form, you can then do, along the lines from this answer -
form.courses.queryset = Course.objects.filter(professor__in=[professor.id,])
Note that I've put filtered on a list here, which only has one item - it does give you scope to expand, or to use a queryset for more complicated functions later.
Tweak as appropriate if you're using class-based views. :)

Sum of fields for filtered queryset using django_filters

I have the following view
class AuthorList(FilterView):
model = Author
filterset_class = AuthorFilter
context_object_name = 'authors'
In the template, one of the field is {{ author.value }}, which is an integer.
What I would like to do is to show the sum of all {{ author.value }} in my template, but in a dynamic way (if some filters are used, the sum is updated with the current Queryset).
I have tried adding extra context with get_context_data but I couldn't find out how to make it in a dynamic way.
EDIT
tried this, still not working:
#property
def get_sum_values(self):
sum_values = self.objects.all().aggregate(Sum('value'))['value__sum']
return sum_values
and in the template: {{ authors.get_sum_values }}
I have also tried to add a print statement in the property, but nothing shows up, so I guess the function is not even loaded.
my models:
class Author(models.Model):
name = models.CharField(max_length=50, blank=True, null=True)
value = models.IntegerField(null=True, blank=True)

Have you tried doing the sum in the model as a function ?
#property
def wallet_amount_guests(self):
data_payments = self.user.earnings_set.filter(transaction_type='g').aggregate(Sum('amount'))['amount__sum']
if data_payments == None:
data_payments = 0
return data_payments
The above is just an example I have used before. You can then call in the html as blah.function_name

Iterating 2 querysets in Django html?

I have two querysets. My first Queryset (services) has all of my service objects. My second Queryset (rating_values) has all of my rating values, where each index corresponds to the index in the services Queryset. For example services[1] corresponds with rating_values[1].
How do I loop through these two queries in an html page in django so so that I can display the service name along with the corresponding rating value?
To be clear, services contains service objects and rating_values contains decimal values. I pass the variables like this:
return render_to_response('services/display_services.html', {'user': request.user, 'services':services, 'rating_values': rating_values })
I would like to do something like this:
{% for service in services %}
<p> {{service.service_name}} : {{ corresponding rating_value}} </p>
Edit
Here is my Service model:
class Service(models.Model):
user_id= models.IntegerField(default=1)
service_name = models.CharField(max_length=100)
address = models.CharField(max_length=200)
def __str__(self): # __unicode__ on Python 2
return self.service_name
Here is my Rating Model:
class Rating(models.Model):
service_id= models.IntegerField(default=1)
service_name= models.CharField(max_length=200)
number_of_ratings = models.IntegerField()
total_rating_value = models.IntegerField()
rating_average = models.FloatField()
def __str__(self): # __unicode__ on Python 2
return self.service_name

Just to answer the original question as well.
If you for some reason don't want a database relation between the models, you could convert the querysets to lists and zip them in the view, turning the querysets to a list of tuples.
view:
return render_to_response(
'services/display_services.html',
context_instance={
'user': request.user,
'services_and_ratings': zip(
services.all(),
rating_values.all()
)
}
)
template:
{% for service, rating in services_and_ratings %}
<p> {{ service.service_name }} : {{ rating.rating_average }} </p>

You can establish the relationship right in the model.
class Rating(models.Model):
service= models.OneToOneField(Service, primary_key=True)
service_name= models.CharField(max_length=200)
number_of_ratings = models.IntegerField()
total_rating_value = models.IntegerField()
rating_average = models.FloatField()
....
You can then pass services and get the corresponding ratings..
{% for service in services %}
<p> {{service.service_name}} : {{ service.rating.rating_average }} </p>