如何根据 django 中的当前登录用户获取所有费用的总和？

Question

I am using to sum all the expense values which are assigned to an user. I am not able to display it in my webpage. How can i do that? The models.py code is as follows:

class expense(models.Model):
   Expensecat=(('food','Food'),
                ('transportation','Transportation'),
                ('education','Education'),
                ('health','Health'),
                ('clothes','Clothes'),
                ('beauty','Beauty'),
                ('hosuehold','Household'),
               )
   ExpenseAmount=models.FloatField(max_length=100)
   Category=models.CharField(max_length=200,choices= Expensecat)
   Description=models.TextField(max_length=200)
   Date=models.DateTimeField(default=timezone.now)
   user=models.ForeignKey(User,on_delete=models.CASCADE)

Views.py

def home(request):
    try:
        expense_total = expense.objects.filter(user=request.user).aggregate(expenses=Sum('ExpenseAmount'))
    except TypeError:
        print('No data') 

    data = {
            'Expense':expense_total['expenses'],       
           }
    return render(request, 'budget/home.html', data )

HTML CODE:

 <div class="col-lg-3 col-md-6 d-flex stat my-3">
                      <div class="mx-auto">
                          <h6 class="text-muted">Expense</h6>
                          <h3 class="font-weight-bold">{{ Expense.expenses }}</h3>
                          <h6 class="text-success"></h6>
                      </div>

Answer 1

You assign this to the Expense variable, so you render this with Expense , so not Expense.expenses , you already "unwrapped" the value from the dictionary:

{{  }}

---

Note : When you make calculations with money, it is better to use a DecimalField [Django-doc] , not a FloatField [Django-doc] . Floats can generate rounding errors when you perform calculations. You can also use django-money [GitHub] to specify a MoneyField . This has also specifies a currency, and can convert money to a different currency.