for

Loop over each item in a sequence. For example, to display a list of users provided in a variable called users:

<h1>Members</h1>
<ul>
  {% for user in users %}
    <li>{{ user.username | e }}</li>
  {% endfor %}
</ul>

If you do need to iterate over a sequence of numbers, you can use the .. operator:

{% for i in 0..10 %}
  * {{ i }}
{% endfor %}

The above snippet of code would print all numbers from 0 to 10. It can be also useful with letters:

{% for letter in 'a'..'z' %}
  * {{ letter }}
{% endfor %}

The .. operator can take any expression at both sides:

{% for letter in 'a'|upper..'z'|upper %}
  * {{ letter }}
{% endfor %}

The loop variable

Inside of a for loop block you can access some special variables:

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.parent`	The parent context

{% for user in users %}
    {{ loop.index }} - {{ user.username }}
{% endfor %}

If no iteration took place because the sequence was empty, you can render a replacement block by using else:

<ul>
  {% for user in users %}
    <li>{{ user.username | e }}</li>
  {% else %}
    <li><em>no user found</em></li>
  {% endfor %}
</ul>

By default, a loop iterates over the values of the sequence. You can iterate on keys by using the keys filter:

<h1>Members</h1>
<ul>
    {% for key in users | keys %}
        <li>{{ key }}</li>
    {% endfor %}
</ul>

You can also access both keys and values:

<h1>Members</h1>
<ul>
    {% for key, user in users %}
        <li>{{ key }}: {{ user.username | e }}</li>
    {% endfor %}
</ul>

You might want to iterate over a subset of values. This can be achieved using the slice filter:

<h1>Top Ten Members</h1>
<ul>
    {% for user in users | slice(0, 10) %}
        <li>{{ user.username | e }}</li>
    {% endfor %}
</ul>