django:TypeError:'tuple'对象不可调用

Getting a type error, 'tuple' object is not callable. Any idea what it could be? (dont worry about the indentation. It copies in weird.) I'm trying to create choices based on PackSize of storeliquor.

Views.py:

def storeliquor(request, store_id, liquor_id):        
a = StoreLiquor.objects.get(StoreLiquorID=liquor_id)
s = Store.objects.get(StoreID=store_id)
x = Order.objects.get(storeID=s, Active=True)
y = a.OffPremisePrice
c = a.BottleSize

g = request.POST.get('OrderAmount', '')
b = a.PackSize
h = b*2
d = b*3
e = b*4
r = b*5
if c == "1750 ML":
    pack_size = (
        ('1', '1')
        ('3', '3')
        (b, b)
        (h, h)
        (d, d)
        (e, e)
        (r, r)
    )
elif c == "1000 ML":
    pack_size = (
        ('1', '1')
        ('3', '3')
        ('6', '6')
        (b, b)
        (h, h)
        (d, d)
        (e, e)
        (r, r)
    )
elif c == "750 ML":
    pack_size = (
        ('1', '1')
        ('3', '3')
        ('6', '6')
        (b, b)
        (h, h)
        (c, d)
        (e, e)
        (r, r)
    )     
elif c == "375 ML":
    pack_size = (
        ('3', '3')
        ('6', '6')
        ('12', '12')
        (b, b)
        (h, h)
        (d, d)
        (e, e)
        (r, r)
    )        
elif c == "200 ML":
    pack_size = (
        ('12', '24')
        ('24', '24')
        (b, b)
        (c, c)
        (c, d)
        (e, e)
        (r, r)
    ) 
else:
    pack_size = (
        (b, b)
        (c, c)
        (c, d)
        (e, e)
        (r, r)
    )        




if request.method == "POST":
    f = AddToOrderForm(request.POST)

    if f.is_valid():
        z = f.save(commit=False)
        z.TotalPrice = (float(y)) * (float(g))
        z.storeliquorID = a
        z.orderID = x

        z.save()        

    return HttpResponseRedirect('/stores/get/%s' % store_id)

else:
    f = AddToOrderForm()
    f.fields['OrderAmount'].choices = pack_size      
args = {}


args['liquor'] = a
args['s'] = s
args['form'] = f   

return render(request,'storeliquor.html', args)

模型文件:

class LiquorOrder(models.Model):

LiquorOrderID = models.AutoField(primary_key=True)
storeliquorID = models.ForeignKey(StoreLiquor)
orderID = models.ForeignKey(Order)
OrderAmount = models.CharField('Order Amount', max_length=3)
TotalPrice = models.DecimalField('Total Price', max_digits=5, decimal_places=2)
StorePrice = models.DecimalField('Store Price', max_digits=5, decimal_places=2)

表格文件:

class AddToOrderForm(forms.ModelForm):

class Meta:
    model = LiquorOrder
    fields = ('OrderAmount', 'StorePrice')

解决方案

中间缺少逗号(,):

>>> ((1,2) (2,3))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'tuple' object is not callable

加逗号:

>>> ((1,2), (2,3))
((1, 2), (2, 3))