CODEWITHSUNDEEP
pythondjango
rahul.m
rahul.m

Reputation: 5854

Python/Django recursive model into tree structrue dict

I have a Django model

class Category(models.Model):
    parent = models.ForeignKey('Category', null=False, blank=False)
    category_name = models.CharField(max_length=55,null=False, blank=False)
    status = model.BooleanField(default=True)

I want to create recursive which return tree structure dict.

e.g

[
    {
        'category_name': 'vehical',
        'id': 1,
        'children' : [
            {
                'category_name': 'cars',
                'id': 11,
                'children': [
                    {
                        'category_name': 'sport cars',
                        'id': 20
                    }               
                ]               
            }       
        ]
    }
]



>>> category = Category.objects.all()
>>> get_tree(category)

Upvotes: 2

Views: 1056

Answers (1)

ruddra
ruddra

Reputation: 51978

I think you need to change your ForeignKey relationship to self, for referencing itself. Also, for simplicity of implementation, let us add related_name='children'(doc) and make it nullable(null=True) to denote it as a root node(s).

class Category(models.Model):
    parent = models.ForeignKey('self', null=True, blank=True, related_name='children')
    category_name = models.CharField(max_length=55,null=False, blank=False)
    status = models.BooleanField(default=True)

Then we can do following implementation:

from django.forms.models import model_to_dict

def get_tree(category):
    tree = model_to_dict(category, fields=['category_name', 'status', 'id'])
    if category.children.all().exists():
       children = list()
       for child in category.children.all():
          children.append(get_tree(child))
       tree['children'] = children
    return tree

final_tree = list()
for category in Category.objects.filter(parent__isnull=True):
    final_tree.append(get_tree(category))
print(final_tree)

Upvotes: 4

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