python - Appropriate way to override Model __getattr__ in 1.4 -

what's appropriate way of overriding model class's getattr in django 1.4?

i have model structure like:

class main(models.model):     [blah]  class detail(models.model):    main = models.foreignkey(main)    name = models.charfield(max_length=255)    value= models.charfield(max_length=255) 

i had overridden main.getattr_ reference detail records though normal main attributes. e.g. simple meta- model pattern like

>>> m = main.objects.create() >>> detail.objects.create(main=m, name='name', value='value') >>> print m.name 'value' 

to this, pre-1.4 getattr looked like:

def __getattr__(self, attrname):     qs = self.details.filter(name=attrname)     c = len(qs)     if c == 0:         raise attributeerror     elif c == 1:         return qs[0].value     else:         return [d.value d in qs] 

this worked until upgraded 1.4. types "attribute x not exist" errors. tried following, had no luck. seems conflict "_*_cache" attributes django generates foreignkey references.

def __getattr__(self, attrname):     try:         return super(main, self).__getattr__(attrname)     except attributeerror:         pass     qs = self.details.filter(name=attrname)     c = len(qs)     if c == 0:         raise attributeerror     elif c == 1:         return qs[0].value     else:         return [d.value d in qs] 

how resolve this?

digging through new model code, seems backend has been changed substantially, model class no longer has __getattr__ override. instead, need call object.__getattribute__, base model inherits from. however, django stores cached data in special attributes, need handled.

my new __getattr__ looks like:

def __getattr__(self, attrname):     try:         return super(main, self).__getattribute__(attrname)     except attributeerror:         if attrname.startswith('_prefetched'):             raise     qs = self.details.filter(name=attrname)     c = len(qs)     if c == 0:         raise attributeerror     elif c == 1:         return qs[0].value     else:         return [d.value d in qs]