Multiple try except in a serializer Django - django

Question

I have a Warehouse model like the following:
class ShelfBin(models.Model):
bin_id = models.IntegerField(default=0)
bin_name = models.CharField(max_length=50, default=0)
class UnitShelf(models.Model):
shelf_id = models.IntegerField(default=0)
shelf_name = models.CharField(max_length=50, default=0)
bin = models.ManyToManyField(ShelfBin, blank=True)
class AisleUnit(models.Model):
unit_id = models.IntegerField(default=0)
unit_name = models.CharField(max_length=50, default=0)
shelf = models.ManyToManyField(UnitShelf, blank=True)
class ZoneAisle(models.Model):
aisle_id = models.IntegerField(default=0)
aisle_name = models.CharField(max_length=50, default=0)
unit = models.ManyToManyField(AisleUnit, blank=True)
class WarehouseZone(models.Model):
zone_id = models.IntegerField(default=0)
zone_name = models.CharField(max_length=50, default=0)
aisle = models.ManyToManyField(ZoneAisle, blank=True)
class Warehouse(models.Model):
owner = models.ForeignKey(User, on_delete=models.CASCADE)
name = models.CharField(max_length=250, default=0)
address = models.CharField(max_length=500, default=0)
zones = models.ManyToManyField(WarehouseZone, blank=True)
for this I have created a serializer like the following:
class WarehouseSerializer(serializers.ModelSerializer):
zones = WarehouseZonesSerializer(many=True)
class Meta:
model = Warehouse
fields = "__all__"
def create(self, validated_data):
print("validated data warehouse", validated_data)
zone_objects = validated_data.pop('zones', None)
instance = Warehouse.objects.create(**validated_data)
for item in zone_objects:
aisle_objects = item.pop('aisle')
wz_obj = WarehouseZone.objects.create(**item)
for data in aisle_objects:
unit_objects = data.pop('unit')
za_obj = ZoneAisle.objects.create(**data)
for u_data in unit_objects:
shelf_objects = u_data.pop('shelf')
au_obj = AisleUnit.objects.create(**u_data)
for s_data in shelf_objects:
bin_objects = s_data.pop('bin')
us_obj = UnitShelf.objects.create(**s_data)
for b_data in bin_objects:
b_obj = ShelfBin.objects.create(**b_data)
us_obj.bin.add(b_obj)
au_obj.shelf.add(us_obj)
za_obj.unit.add(au_obj)
wz_obj.aisle.add(za_obj)
instance.zones.add(wz_obj)
return instance
Now the problem is that sometimes warehouse can have zone, aisle, units, etc(all 5 sub-levels) but sometimes it can only be 1,2 or 0 level deep
and in that cases it raises error like this :
aisle_objects = item.pop('aisle')
KeyError: 'aisle'
So do I have to use try and except at each level of the loop or is there a better way to handle these exceptions?