'ManyToManyField' queries - django

Question

I'm advancing with the web app I asked about earlier.
Currently, my models.py is
from django.db import models
from unittest.util import _MAX_LENGTH
class Alimento(models.Model):
INTOLERANCIAS = (
('00', 'Ninguna'),
('GL', 'Gluten'),
('CR', 'Crustáceos'),
('HU', 'Huevos'),
('FS', 'Frutos Secos'),
('AP', 'Apio'),
('MO', 'Mostaza'),
('SE', 'Sésamo'),
('PE', 'Pescado'),
('CA', 'Cacahuetes'),
('SO', 'Sulfitos'),
('SJ', 'Soja'),
('LA', 'Lácteos'),
('AL', 'Altramuz'),
('ML', 'Moluscos'),
('CA', 'Cacao'),
)
nombre = models.CharField(max_length=60)
intolerancia = models.CharField(max_length=2, choices=INTOLERANCIAS)
def __str__(self):
return self.nombre
class Receta(models.Model):
nombre = models.CharField(max_length=100)
raciones = models.IntegerField(default=1)
preparacion = models.TextField(default='')
consejos = models.TextField(blank=True)
ingredientes = models.ManyToManyField(Alimento, through='Ingrediente', related_name='ingredientes')
def __str__(self):
return self.nombre
def getIntolerancias(self):
ing = self.ingredientes.all()
intolerancias = []
for i in ing:
alimentos = i.alimento.all()
for a in alimentos:
intolerancias.append(a.get_intolerancia_display())
return intolerancias
class Ingrediente(models.Model):
receta = models.ForeignKey('recetas.Receta', on_delete=models.CASCADE)
alimento = models.ManyToManyField(Alimento)
cantidad = models.FloatField(default=0)
descripcion = models.CharField(max_length=60, blank=True)
def __str__(self):
return self.alimento.__str__()
the method getIntolerancias is supposed to list the food intolerances related to each of the ingredients of a given recipe (Receta). To do that, I try to get the queryset of ingredients (Ingrediente) with ing = self.ingredientes, but when I try it on shell I get this error message
Traceback (most recent call last): File "/usr/lib/python3.5/code.py", line 91, in runcode
exec(code, self.locals) File "<console>", line 1, in <module> File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related_descriptors.py", line 476, in __get__
return self.related_manager_cls(instance) File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related_descriptors.py", line 758, in __init__
self.target_field_name = rel.field.m2m_reverse_field_name() File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py", line 15, in _curried
return _curried_func(*(args + moreargs), **dict(kwargs, **morekwargs)) File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related.py", line 1504, in _get_m2m_reverse_attr
return getattr(self, cache_attr) AttributeError: 'ManyToManyField' object has no attribute '_m2m_reverse_name_cache'
I've searched for the error, but the answers I've found don't seem to have what I need (I may just don't understand enough to see it does?)
UPDATE
When I run this on the shell I do
g = Receta.objects.get(nombre = 'Gazpacho')
g.getIntolerancias()
I get an error
intolerancias.append(a.get_intolerancia_display()) AttributeError:
'Ingrediente' object has no attribute 'get_intolerancia_display'
However, if I iterate and get the first element of g.ingredientes.all() and call get_intolerancia_display() it does work OK
a = g.ingredientes.all().first()
a.get_intolerancia_display()
'Gluten'

Answer 1

Update after comments:
Documentation about Many-to-many relation
def get_intolerancias(self):
alimentos = self.ingredientes.all() # Give us all alimento of a recetta
intolerancias = []
for a in alimentos:
intolerancias.append(a.get_intolerancia_display())
return intolerancias