Develop Reference

Looping through nested dictionary in Django template

My context dictionary for my Django template is something like the following:
{'key1':'1',
'key2':'2',
'key3':'3',
'key4':{'key5':{'key6':'6', 'key7':'7', 'key8':'8'}}}
I would like to iterate through the dictionary and print something like:
some label = 6
some label = 7
some label = 8
How can I achieve this in my Django template?

What's wrong with this ?
<ul>
{% for key, value in key4.key5.items %}
<li>{{ key }} : {{ value }}</li>
{% endfor %}
</ul>
NB: you didn't ask for looping over all keys in the context, just about accessing key4['key5'] content. if this wasn't wath you were asking for pleasit eadit your question to make it clearer ;-)

I am guessing you want to use a for loop in the django template to do this you must first pass the dictionary to the template in the views file like so make sure you add square brackets around the dictionary like this:
data = [{'key1':'1',
'key2':'2',
'key3':'3',
'key4':{'key5':{'key6':'6', 'key7':'7', 'key8':'8'}}
}]
return render(request,'name of template',{'data':data})
then in the html template:
{% for i in data%}
<p>{{i.key1}}</p>
<p>{{i.key2}}</p>
<p>{{i.key3}}</p>
<p>{{i.key4.key5.key6}}</p>
{% endfor %}
Now when you do the for loop you can access all the iteams in key4 like i have above when I put {{i.key4.key5.key6}}
Here is the docs for the for loop in django templates https://docs.djangoproject.com/en/3.0/ref/templates/builtins/
I am assuming thats what you want to do.

This has worked for me:
{% for key, value in context.items %}
{% ifequal key "key4" %}
{% for k, v in value.items %}
some label = {{ v.key6 }}
some label = {{ v.key7 }}
some label = {{ v.key8 }}
{% endfor %}
{% endif %}
{% endfor %}

If you want to print only what you have mentioned in question then it is possible but if we don't know the exact structure of dictionary then it is possible in django views not in django template.
You can't print value which is also a dictionary one by one in django template,
But you can do this in django view.
Check this post click here and do some changes in views.

Django - How to access elements in list by parent loop counter in template

I have this code
{% for time in listOfTimes %}
{% for booking in someOtherList.forloop.parentloop.counter0 %}
{{ booking }}
{% endfor %}
{% endfor %}
The booking variable does not get printed. I think this was because I cannot access someOtherList by using the forloop counter. How would I get the booking value?

Assuming your data is as follows:
listOfTimes = ['time1', 'time2']
someOtherList = [['booking1', 'booking2'], ['booking3', 'booking4']]
Then in template you can do this:
{% for time in listOfTimes %}
{% for booking in someOtherList|get_index:forloop.counter0 %}
{{ booking }}
{% endfor %}
{% endfor %}
Notice the get_index filter in above code, you need to write this custom filter in your app templatetags:
from django import template
register = template.Library()
#register.filter
def get_index(l, i):
return l[i]
Note: Your two list should be of same size, otherwise an IndexError might be raised.

'for' statements should use the format 'for x in y': while iterating over value retrieved from dictionary using django template

I have a context dictionary entry objectives that maps objective query objects to a list of tests that belong to that objective. Example code:
objectives = Objective.objects.filter(requirement=requirement)
context_dict["requirements"][requirement] = objectives
for objective in objectives:
tests = Test.objects.filter(objective=objective)
context_dict["objectives"][objective] = tests
In my django html template, I iterate over objectives and display them. I then want to iterate over the tests that belong to these objectives. When I do this:
{% for test in {{ objectives|get_item:objective }} %}
I get a TemplateSyntaxError: 'for' statements should use the format 'for x in y':
In the application/templatetags directory, I have:
from django.template.defaulttags import register
...
#register.filter
def get_item(dictionary, key):
return dictionary.get(key)
If instead I make {{ objectives|get_item:objective }} a JS variable, I see that it does indeed produce a list, which I should be able to iterate over. Of course, I can't mix JS variables and the django template tags, so this is only for debugging:
var tests = {{ objectives|get_item:objective }}
var tests = [<Test: AT399_8_1>, <Test: AT399_8_2>, <Test: AT399_8_3>, <Test: AT399_8_4>, <Test: AT399_8_5> '...(remaining elements truncated)...']
How do I iterate over this list in the django template tag?

You cannot user {{...}} inside the {%...%}
What you can try is changing your filter to an assignment tag and using that value in the loop
#register.assignment_tag
def get_item(dictionary, key):
return dictionary.get(key)
And then in your template use it as
{% get_item objectives objective as tests %}
{% for test in test %}
....
{% endfor %}
Instead of all this if your models are proper with foreign keys I would do something like
{% for objective in requirement.objective_set.all %}
{% for test in objective.test_set.all %}
....
{% endfor %}
{% endfor %}
In my context I would pass only the requirement

You already have an answer, but note that dropping the {{ }} tags and keeping everything else the same would have worked fine.
{% for test in objectives|get_item:objective %}

**This is Right Answer for Using Django if else and for loop **
Note :- We Have to Put Key in " " string (Double quotes) some time produce an error so That is good way bcz i faced that problem whwn i Learned
{% if 'numbers'|length > 0 %}
{% for i in numbers %}
{% if i > 20 %}
{{i}}
{% endif %}
{% endfor %}
{% else %}
Empty
{% endif %}

Django - create custom tag to acces variable by index in template

I have a HTML template in django. It get's two variables: list of categories (queryset, as it it returned by .objects.all() function on model in django) and dictionary of contestants. As a key of the dictionary, I'm using id of category, and value is list of contestats.
I want to print name of the category and then all the contestants. Now I have this:
{% for category in categories_list %}
<h1>category.category_name</h1>
{% for contestant in contestants_dict[category.id] %}
{{ contestant }} </br>
{% endfor %}
{% endfor %}
However, when I run it, I get error:
TemplateSyntaxError at /olympiada/contestants/
Could not parse the remainder: '[category.id]' from 'contestants_dict[category.id]'
What I know so far is that I can't use index in template. I thought that {% something %} contains pure Python, but it shoved up it's just a tag. I know that I have to create my own simple_tag, but I don't know how. I read the docs Writing custom template tags, but there is such a little information and I wasn't able to fiqure out how to create (and mainly use in a for loop) a tag, that will take dict, key and return the value. What I tried is:
templatetags/custom_tags.py:
from django import template
register = template.Library()
#register.simple_tag
def list_index(a, b):
return a[b]
and in template:
{% for contestant in list_index contestants_dict category.id %}
But I get TemplateSyntaxError.
Could you please explain/show me how to create the tag, or is there a better way to do this?
Thanks.
//EDIT:
I managed to do it this way:
{% list_index contestants_list category.id as cont %}
{% for contestant in cont %}
it works, but it takes 2 lines and I need to create another variable. Is there any way to do it without it?

If you don't want 2 lines like that you should be able to use a filter i think
#register.filter
def list_index(a, b):
return a[b]
Then the usage like this
{% for contestant in contestants_dict|list_index:category.id %}
{{ contestant }} </br>
{% endfor %}

Django use value of template variable as part of another variable name

I currently have this for loop inside my template:
{% for i in 1234|make_list %}
I would like to obtain something like this inside loop:
{{ form.answer_{{ i }} }}
I am aware that the above line is not valid (it raises TemplateSyntaxError), but I would like to know if there is any way to use the value of i as part my other variable name.

First, you would need a custom template filter to mimic getattr() functionality, see:
Performing a getattr() style lookup in a django template
Then, you would need add template filter for string concatenation:
{% load getattribute %}
{% for i in 1234|make_list %}
{% with "answer_"|add:i as answer %}
{{ form|getattribute:answer }}
{% endwith %}
{% endfor %}