'Return the default value to use when validating data if no input
is provided for this field.
If a default has not been set for this field then this will simply
raise `SkipField`, indicating that no value should be set in the
validated data for this field.'

def get_default(self):

    if ((self.default is empty) or getattr(self.root, u'partial', False)):
        raise SkipField()
    if callable(self.default):
        if hasattr(self.default, u'set_context'):
            self.default.set_context(self)
        return self.default()
    return self.default
