Django throwing "invalid literal for int() with base 10: ''" when trying to save object attribute

Question

Django keeps throwing the following when I try and save the addition of two object attributes.

invalid literal for int() with base 10: ''

The view is:

def buy_pack(request, pack_name):
if request.method == 'POST':
    form = CardForm(request.POST, request.user)
    pack = Pack.objects.get(name=pack_name)
    stripe_user = request.user.username

    if form.is_valid():
        token = request.POST['stripeToken']
        charge = stripe.Charge.create(
            amount=pack.cost,
            currency="usd",
            card=token,
            description=stripe_user+"_"+pack.name,
        )

        datestring = charge.created
        dt = datetime.datetime.fromtimestamp(float(datestring))
        new_purchase = Purchase(user=request.user, date_time=dt, pack=pack, payment_id=charge.id, last_4_digits=charge.card.last4)
        new_purchase.save()

        user_profile = request.user.get_profile()
        t = user_profile.videos_remaining + pack.videos_allowed
        user_profile.videos_remaining = t
        user_profile.save()

The models in question are:

class UserProfile(models.Model):
    user = models.ForeignKey(User, unique=True)
    name = models.CharField(max_length=50)
    videos_remaining = models.IntegerField(default=1)
    last_4_digits = models.IntegerField(max_length=4, blank=True)
    stripe_id = models.CharField(max_length=255, blank=True)

    def __unicode__(self):
        return self.name

And:

class Pack(models.Model):
    name = models.CharField(max_length=25)
    videos_allowed = models.IntegerField()
    cost = models.IntegerField()

    def __unicode__(self):
        return self.name

Traceback is:

Traceback:
File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Users/Jeff/Dropbox/xxxxx/Code/thankyouvid/../thankyouvid/main/views.py" in buy_pack
  48.           user_profile.save()
File "/Library/Python/2.7/site-packages/django/db/models/base.py" in save
  460.         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "/Library/Python/2.7/site-packages/django/db/models/base.py" in save_base
  526.                         rows = manager.using(using).filter(pk=pk_val)._update(values)
File "/Library/Python/2.7/site-packages/django/db/models/query.py" in _update
  491.         return query.get_compiler(self.db).execute_sql(None)
File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  869.         cursor = super(SQLUpdateCompiler, self).execute_sql(result_type)
File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  725.             sql, params = self.as_sql()
File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py" in as_sql
  834.                 val = field.get_db_prep_save(val, connection=self.connection)
File "/Library/Python/2.7/site-packages/django/db/models/fields/subclassing.py" in inner
  28.             return func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/fields/subclassing.py" in inner
  28.             return func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/fields/__init__.py" in get_db_prep_save
  276.         return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/Library/Python/2.7/site-packages/django/db/models/fields/subclassing.py" in inner
  53.             return func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/fields/subclassing.py" in inner
  53.             return func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/fields/__init__.py" in get_db_prep_value
  271.             value = self.get_prep_value(value)
File "/Library/Python/2.7/site-packages/django/db/models/fields/__init__.py" in get_prep_value
  876.         return int(value)

Exception Type: ValueError at /buy_pack/most/
Exception Value: invalid literal for int() with base 10: ''

For reference the stored value for user_profile.videos_remaining is 1 and the stored value for pack.videos_allowed is 100. I am expecting it to add the two values together and store them as 101 in the user_profile.videos_remaining object attribute.

If you can provide any help I would greatly appreciate it.

EDIT: The problem ended up being that I was not passing a value for the integer field last_4_digits. It seems that this happens if you have a integerField with blank=True and don't submit a value for it.

Answer 1

The problem for me was that I was using required=False, disabled=True, that didn't send the data to the server for that field. I changed to

amount_payments = CharField(widget=TextInput(attrs={'readonly': 'readonly'}))

Answer 2

This type of error is occur when an "Integer" inupt contains empty or string value like " 'id' ", " '.'.", etc. So, you have to find out that for what this type of input you get.

Answer 3

I experienced this error message as well in a Django population script with a ForeignKey having both blank=True and null=True, and passing '' as argument to objects.get_or_create().

I fixed the issue by passing argument=None. The None part is the clue.

Answer 4

The problem ended up being that I was not passing a value for the integer field last_4_digits. It seems that this happens if you have a integerField with blank=True and don't submit a value for it.