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Assign multiple variables in a with statement after returning multiple values from a templatetag

Is there a way to assign multiple variables in a with statement in a django template. I'd like to assign multiple variables in a with statement after returning multiple values from a templatetag
My use case is this:
{% with a,b,c=object|get_abc %}
{{a}}
{{b}}
{{c}}
{% endwith %}

I don't think it's possible without a custom templatetag.
However if your method returns always the same length you can do it more compact like this:
{% with a=var.0 b=var.1 c=var.2 %}
...
{% endwith %}

I'm not sure that this as allowed, however from docs multiple assign is allowed.
But you can assign these 3 variables to 1 variable, which will make it tuple object, which you can easily iterate by its index.
{% with var=object|get_abc %}
{{ var.0 }}
{{ var.1 }}
{{ var.2 }}
{% endwith %}

Its not supported and its not a flaw of Django Template Language that it doesn't do that, its Philosophy as stated in the docs:
Django template system is not simply Python embedded into HTML. This
is by design: the template system is meant to express presentation,
not program logic
What you could do is prepare your data on Python side and return appropriate format which will be easy to access in template, so you could return a dictionary instead and use dotted notation with key name:
{# assuming get_abc returns a dict #}
{% with var=object|get_abc %}
{{ var.key_a }}
{{ var.key_b }}
{{ var.key_c }}
{% endwith %}

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 %}

Python/Django: Simple Django Template

Hi I am using App Engine/Python to do a simple website. I have some trouble with a Django template problem.
In short, I want to use a "ShortName" to access a "LongName".
The soource code:
LongName={"so":"stackoverflow","su":"superuser"}
ShortName=['so','su']
Then I pass these two parameters to the templates.
In the template I write:
{% for aname in ShortName %}
{{ aname }} stands for {{ LongName.aname }},
{% endfor %}
The output is:
so stands for, su stands for
No error is given. The LongName.aname wont work.
I have no idea whats wrong.

This is trying to access LongName['aname'], not LongName[aname].
You might have to write a custom template tag/filter to get this to work. This Django bug (marked WONTFIX) has a simple implementation:
def get(d, key):
return d.get(key, '')
register.filter(get)
which you would use by
{{ LongName|get:aname }}
after adding it to your app (that SO answer shows how to do it on GAE).
You could also pre-make a variable to loop over in the view, by passing in
# in view
name_abbrevs = [(k, LongName[k]) for k in ShortName]
# in template
{% for short_name, long_name in name_abbrevs %}
{{ short_name }} stands for {{ long_name }}
{% endif %}
If you really don't want to add a template tag -- which isn't that bad! you just make one file! :) -- or pass in an extra variable, Vic's approach will let you do this without touching the Python files at all. As he mentions, it involves a lot of pointless iteration, but it'll work fine for small lists.

Django templates have a drawback here. I've been in the same situation before. What you have to do is iterate over all the keys in LongName, and check if the key you're looking for matches the ShortName. Here you go:
{% for aname in ShortName %}
{% for short_version, long_version in LongName %}
{% if aname == short_version %}
{{ aname }} stands for {{ long_version }},
{% endif %}
{% endfor %}
{% endfor%}
It's inefficient, and essentially a pointless O(n^2) mechanism. However, there's no better way in pure Django templates to refer to entries of a dict by a variable name.

Django templates: accessing the previous and the following element of the list

I am rather new to django templates and have an impression that I have not understood some basics.
I have a list of elements and I need to render an element of the list based on conditions against the the previous and the next elements (in case the following or the previous elements are hidden, I need to mark the current element as border element).
How can I reference the previous and the following elements within a for loop in Django templates?

You could write a custom template filter for next and previous:
def next(value, arg):
try:
return value[int(arg)+1]
except:
return None
and in the template:
{% for ... %}
{% with list|next:forloop.counter0 as next %}
{% if next.is_hidden %}
...
{% endif %}
{% endwith %}
{% endfor %}
but like others have said, there are probably more elegants solutions doing this via your view

You can't do this strictly with built-in template tags. You need to involve some Python.
One method would be to zip the list with itself:
new = ([(None, orig[0], orig[1])] +
zip(orig, orig[1:], orig[2:]) +
[(orig[-2], orig[-1], None)])
and pass that to the template, then loop over it like this:
{% for prev, current, next in new %}
{% if prev.hidden or next.hidden %}
BORDER
{% endif %}
{{ current }}
{% endfor %}

You really shouldn't use the Django templates for this kind of logic. You have your views to handle it. I would figure out which elements of the list are borders and pass in an extra parameter that I can handle in the template using a simple if statement. For example:
{% for element,is_border in data.items %}
{% if is_border %}
do something
{% endif %}
{% endfor %}
There are tons of similar ways you can do this. I presented just one example.

You can create an external tag which does that but django templating system which was build to be lightweight has no such feature in for loops.

how to run this code in django template

this is my code :
{% for i,j in enumerate(a) %}
{{i}} ,{{j}}
{% endfor%}
but , it show a error , i think it cant run the enumerate method ,
so how to run the enumerate in django template ,
thanks

The template subsystem has some special constructs built into the for/endfor block that allows you to access the current index of the loop without having to call enumerate.
{% for j in a %}
{{ forloop.counter0 }}, {{ j }}
{% endfor %}
While this snippet solves your immediate problem, if you're expecting to have access to Python builtins and other Python constructs inside your Django templates, you may be misunderstanding the sandbox that it provides/enforces.

you can use {{ forloop.counter }} or {{ forloop.counter0 }} for the same effect, the latter is 0-indexed, thus more like enumerate.

{% for item in a %}
{{ forloop.counter }}, {{ item }}
{% endfor %}
Link related

Django template makes up the presentation layer and are not meant for logic. From the docs
If you have a background in programming, or if you’re used to languages which mix programming code directly into HTML, you’ll want to bear in mind that the Django template system is not simply Python embedded into HTML. This is by design: the template system is meant to express presentation, not program logic.
Now to get the same functionality in Django, you will have to complete your logic in the views.
views.py
def my_view(request, ...):
....
enumerated_a = enumerate(a);
....
return render_to_response('my_template.html', {'enumerated_a ': enumerated_a }..)
Now enumerate function returns an enumerate object which is iterable.
my_template.html
{% for index, item in enumerated_a %}
{{ index }},{{ item }}
{% endfor %}
Although I think you can probably change it to an enumerated list and use it like that as well.

If however you need to use a function within a template, i suggest you create a filter or a tag instead. For reference, check out http://docs.djangoproject.com/en/1.2/howto/custom-template-tags/