How can I use a property inside another property? Django

Question

I have the following model with three properties to know the consumption according to the reading:

class ConsElect(models.Model):
    pgd = models.ForeignKey(TipoPGD, on_delete=models.CASCADE, related_name='consumoelect')
    data= models.DateField(default=datetime.now)  
    read_morning = models.IntegerField(default=0)
    read_day = mod

def get_rm(self):
    c_m = list(ConsElect.objects.filter(data__gt=self.data).values('read_morning')[0:1])    
    return ((c_m[0]['read_morning '] - self.read_morning ))    
    cons_m= property(get_rm)

def get_rd(self):
    c_d = list(ConsElect.objects.filter(data__gt=self.data).values('read_day')[0:1])    
    return ((c_d[0]['read_day'] - self.read_day))    
    cons_d= property(get_rd)

def get_total(self):             #It's not correct, I don't know how to implement it
    return cons_d + cons_m       #I need to get the sum of the above two properties

I need a third property in the model to store the sum of the two previous properties, how can I call the two previous properties inside the new property

Asked By: Julio Cesar Sori Gomez

||

Source

Answer 1

I suspect you want something like this.

class ConsElect(models.Model):
    pgd = models.ForeignKey(TipoPGD, on_delete=models.CASCADE, related_name='consumoelect')
    data= models.DateField(default=datetime.now)  
    read_morning = models.IntegerField(default=0)
    read_day = mod

    @property
    def cons_m(self):
        c_m = list(ConsElect.objects.filter(data__gt=self.data).values('read_morning')[0:1])    
        return ((c_m[0]['read_morning '] - self.read_morning ))    

    @property
    def cons_d(self):
        c_d = list(ConsElect.objects.filter(data__gt=self.data).values('read_day')[0:1])    
        return ((c_d[0]['read_day'] - self.read_day))    

    def get_total(self): 
        return self.cons_d + self.cons_m

A property referenced via an instance attribute causes the getter for that property to be called. Typically, you use property as a decorator as you rarely need access to the getter under a separate name. (If you need access to the getter at all, you can access it via the fget attribute of the property itself, e.g. cons_m.fget.)

Answered By: chepner

How can I use a property inside another property? Django

Question:

Answers: