classic: unsupported operand type(s) for +: 'int' and 'NoneType'

[makayabou]

Hello,

I'm sorry for that trivial problem, but I'm still a bit lost...

[code]

#In models.py:

class Ordi(models.Model):

RAM_CAP_1 = 1024

RAM_CAP_2 = 2048

RAM_CAP_CHOICES = (

(RAM_CAP_1, u'1G'),

(RAM_CAP_2, u'2G'),

)

ram_1 = models.IntegerField("memory slot 1", max_length=10, choices=RAM_CAP_CHOICES, null= True, blank=True)

ram_2 = models.IntegerField("memory slot 2", max_length=10, choices=RAM_CAP_CHOICES, null= True, blank=True)

def ram_total(self):

ram_tot = self.ram_capacite_1 + self.ram_capacite_2

#

# Here, python can't contenate int and NoneType...

#

return ram_tot

def maintenus(self):

ordis_maintenus = self.maintenance_set.all()

for o in ordis_maintenus:

return o.__unicode__

    def __unicode__(self):

        return 'ordi '+unicode(self.id)+' - '+self.renvoios()

class Maintenance(models.Model):

    ordi = models.ForeignKey(Ordi)

    def __unicode__(self):

        return self.titre + " du " +self.date_sortie.strftime('%m/%d/%Y')

        

[/code]

[makayabou]

It's  ram_tot = self.ram_1 + self.ram_2

that returns me "cannot contenate int and NOne

[Bill Blanchard]

If you allow Null values in your model and one of the two is being populated with Null, then you'll get the error you're seeing.  Example:

Form:

ram_1 = 56

ram_2 = Null (None)

56 + Null (None) doesn't work.

What you should do instead is set Null to FALSE in both your field declarations and set a default value (it could be zero if you want, but since you have two choices, you can make it one of the two as well).  You could leave it as null=True and set a default value, but that seems like bad practice.

Bill

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