CODEWITHSUNDEEP
pythondjangodictionary
user585936
user585936

Reputation:

Django template syntax for nested dictionary item using variable names

On a Django template page, I'm trying to access the value inside a nested dictionary. 

books = 
 { 
   1: { 1: 'Alice', 2: 'Bob', 3: 'Marta' }, 
   2: { 1: 'Alice', 3: 'Marta' }, 
   3: { 1: 'Alice', 2: 'Bob' }, 
 }

Somewhere on my page, I have these two variables

info.id = 1
detail.id = 2

What I want to do is print (if it exists) the item books[1][2], or in other words books[info.id][detail.id]. I ran into trouble because I couldn't access this nested variable. This got solved here. However, the solution proposed was to access nested dictionary items using the dot notation. But the problem is that this doesn't seem to work when using variables. Using that logic, I would do:

{{ books.info.id.detail.id }}

But this doesn't yield any result. How should I approach the situation when using variables to access the items in a dictionary? Do note that the actual item may or may not exist, which is why I run into trouble using books[info.id][detail.id]

Upvotes: 0

Views: 371

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599460

You can't do this in the template directly. You'll need to use a custom template tag. This would work:

@register.simple_tag
def nested_get(dct, key1, key2):
    return dct.get(key1, {}).get(key2)

Now you can use it in the template:

{% load my_tags_library %}
{% nested_get books item.id detail.id %}

Upvotes: 1

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