How to output loop.counter in python jinja template?
I want to be able to output the current loop iteration to my template.
According to the docs, there is a loop.counter variable that I am trying to use:
<ul>
{% for user in userlist %}
<li>
{{ user }} {{loop.counter}}
</li>
{% if loop.counter == 1 %}
This is the First user
{% endif %}
{% endfor %}
</ul>
But is being outputed to my template. What is the correct syntax?
Solution 1:
The counter variable inside the loop is called loop.index in Jinja2.
>>> from jinja2 import Template
>>> s = "{% for element in elements %}{{loop.index}} {% endfor %}"
>>> Template(s).render(elements=["a", "b", "c", "d"])
1 2 3 4
In addition to loop.index, there is also
-
loop.index0(index starting at0) -
loop.revindex(reverse index; ending at1) -
loop.revindex0(reverse index; ending at0) - Even more at http://jinja.pocoo.org/docs/templates/.
Solution 2:
Inside of a for-loop block, you can access some special variables, such as loop.index (but not loop.counter). From the official docs:
| Variable | Description |
|---|---|
loop.index |
The current iteration of the loop. (1 indexed) |
loop.index0 |
The current iteration of the loop. (0 indexed) |
loop.revindex |
The number of iterations from the end of the loop (1 indexed) |
loop.revindex0 |
The number of iterations from the end of the loop (0 indexed) |
loop.first |
True if first iteration. |
loop.last |
True if last iteration. |
loop.length |
The number of items in the sequence. |
loop.cycle |
A helper function to cycle between a list of sequences. |
loop.depth |
Indicates how deep in a recursive loop the rendering currently is. Starts at level 1 |
loop.depth0 |
Indicates how deep in a recursive loop the rendering currently is. Starts at level 0 |
loop.previtem |
The item from the previous iteration of the loop. Undefined during the first iteration. |
loop.nextitem |
The item from the following iteration of the loop. Undefined during the last iteration. |
loop.changed(*val) |
True if previously called with a different value (or not called at all). |
Solution 3:
If you are using Django, use forloop.counter instead of loop.counter:
<ul>
{% for user in userlist %}
<li>
{{ user }} {{forloop.counter}}
</li>
{% if forloop.counter == 1 %}
This is the First user
{% endif %}
{% endfor %}
</ul>