models.BooleanField interpret as integer

Question

How can I interpret booleans (or '') as integers 0 or 1? so totals could be 0, 1 or 2, depending on the values of uno and dos.

class foo(models.Model)
    uno  = models.BooleanField()
    dos  = models.BooleanField()
    total = models.PositiveSmallIntegerField(blank=True, default=int(0))
    def save(self, *args, **kwargs):
        # HUMDINGER....
        self.total = int(self.uno) + int(self.dos)
        super(Survey, self).save(*args, **kwargs) # Call the "real" save() method.

This is the error it is throwing for that line...

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

Answer 1

I'm surprised that your BooleanFields have the empty string as their value. Regardless, since booleans evaluate to 0 and 1 in a numeric context, you can just do:

self.total = bool(self.uno) + bool(self.dos)