Django Model default call back not adding beyond 10 - django

Question

I was hoping someone can assist with my issue in that when I used a default callback my 'account_number' field gets an Integrity Error when above 10. Without a default callback, I have no issues and it works.
My Account Model:
def account_number_increment():
last_number = Account.objects.all().order_by("account_number").last()
print("I am the last number")
start_from = AccountSettings.account_number_startfrom
print("I am the start from")
acc_number = '1'
if last_number is None:
print("I am the initiator")
return acc_number
if start_from != '' or start_from is not None:
while Account.objects.all().filter(account_number=start_from).exists():
acc_number_start = int(last_number.account_number) + 1
print("acc # from start from", str(acc_number_start))
return str(acc_number_start)
if last_number:
# last_number.refresh_from_db(fields="account_number")
# last_number.refresh_from_db()
while Account.objects.all().filter(account_number=last_number.account_number).exists():
print("BEFORE addition", last_number.account_number)
new_acc_number = int(last_number.account_number) + 1
print("acc # new number", str(new_acc_number))
return str(new_acc_number)
class Account(models.Model):
name = models.CharField(max_length=100, null=True, blank=True)
address = models.OneToOneField(Address, on_delete=models.SET_NULL, blank=True, null=True,
related_name="account_address")
account_number = models.CharField(max_length=20, default=account_number_increment, null=True, blank=True, unique=True)
# account_number = models.CharField(max_length=20, default='1def') # works with for loop in views.
date_created = models.DateTimeField(auto_now_add=True)
last_modified = models.DateTimeField(auto_now=True)
user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
def __str__(self):
return self.name
My Account_Settings Model
class AccountSettings(models.Model):
account_number_startfrom = models.CharField(max_length=100, default='1', blank=True, null=True)
def __str__(self):
return f'{self.job_number_startfrom}, {self.account_number_startfrom}, {self.invoice_number_startfrom}'
My views
def index(request):
if request.method == 'POST':
form1 = AccountForm(prefix='form1', data=request.POST)
form2 = AccountForm(prefix='form2', data=request.POST)
if form1.is_valid() and form2.is_valid():
form1.save()
form2.save()
print("FORMs SAVED")
return redirect(reverse('account:home'))
else:
user1 = CustomUser.objects.create(username='userFirst')
acc1 = Account.objects.create(name='IamUser40000', user=user1)
print('this is the new 1 ----' + str(acc1.pk) + acc1.name + '--------------')
acc11 = Account.objects.get(pk=acc1.pk)
acc2 = Account.objects.create(name='IamUser3000', user=user1)
print('this is the new 2 ----' + str(acc2.pk) + acc2.name +'--------------')
acc22 = Account.objects.get(pk=acc2.pk)
form1 = AccountForm(prefix='form1', instance=acc11)
form2 = AccountForm(prefix='form2', instance=acc22)
# for loop for non default callback
# num = 3
# for i in range(15):
# name = "IAMUSER"+str(i)
# account_number = str(num)
# Account.objects.create(name=name, account_number=account_number, user=user1)
# num = num + 1
# for loop for default with call back
for i in range(15):
name = "IAMUSER" + str(i)
# Account.objects.create(name=name, account_number=account_number_increment(), user=user1)
Account.objects.create(name=name, user=user1)
context = {
'form1': form1,
'form2': form2,
}
return render(request, 'accounts/index.html', context)
The error:
django.db.utils.IntegrityError: duplicate key value violates unique
constraint "account_account_account_number_a5d74cff_uniq" DETAIL: Key
(account_number)=(10) already exists.