For Loops
A for loop is used for iterating over a sequence, like looping over items in an array, a list, or a dictionary.
Example
{% for x in fruits %}
<h1>{{ x }}</h1>
{% endfor %}
Example
{% for x in cars %}
<h1>{{ x.brand }}</h1>
<p>{{ x.model }}</p>
<p>{{ x.year }}</p>
{% endfor %}
Data From a Model
Data in a model is like a table with rows and columns.
The Member model we created earlier has five rows, and each row has three columns:
| id | firstname | lastname | phone | joined_date |
|---|---|---|---|---|
| 1 | Emil | Refsnes | 5551234 | 2022-01-05 |
| 2 | Tobias | Refsnes | 5557777 | 2022-04-01 |
| 3 | Linus | Refsnes | 5554321 | 2021-12-24 |
| 4 | Lene | Refsnes | 5551234 | 2021-05-01 |
| 5 | Stalikken | Refsnes | 5559876 | 2022-09-29 |
When we fetch data from the model, it comes as a QuerySet object, with a similar format as the cars example above: a list with dictionaries:
<QuerySet [
{
'id': 1,
'firstname': 'Emil',
'lastname': 'Refsnes',
'phone': 5551234,
'joined_date': datetime.date(2022, 1, 5)
},
{
'id': 2,
'firstname': 'Tobias',
'lastname': 'Refsnes'
'phone': 5557777,
'joined_date': datetime.date(2021, 4, 1)
},
{
'id': 3,
'firstname': 'Linus',
'lastname': 'Refsnes'
'phone': 5554321,
'joined_date': datetime.date(2021, 12, 24)
},
{
'id': 4,
'firstname': 'Lene',
'lastname': 'Refsnes'
'phone': 5551234,
'joined_date': datetime.date(2021, 5, 1)
},
{
'id': 5,
'firstname': 'Stalikken',
'lastname': 'Refsnes'
'phone': 5559876,
'joined_date': datetime.date(2022, 9, 29)
}
]>
Example
{% for x in members %}
<h1>{{ x.id }}</h1>
<p>
{{ x.firstname }}
{{ x.lastname }}
</p>
{% endfor %}
Reversed
The reversed keyword is used when you want to do the loop in reversed order.
Example
{% for x in members reversed %}
<h1>{{ x.id }}</h1>
<p>
{{ x.firstname }}
{{ x.lastname }}
</p>
{% endfor %}
Empty
The empty keyword can be used if you want to do something special if the object is empty.
Example
<ul>
{% for x in emptytestobject %}
<li>{{ x.firstname }}</li>
{% empty %}
<li>No members</li>
{% endfor %}
</ul>
The empty keyword can also be used if the object does not exist:
Example
<ul>
{% for x in myobject %}
<li>{{ x.firstname }}</li>
{% empty %}
<li>No members</li>
{% endfor %}
</ul>
Loop Variables
Django has some variables that are available for you inside a loop:
- forloop.counter
- forloop.counter0
- forloop.first
- forloop.last
- forloop.parentloop
- forloop.revcounter
- forloop.revcounter0
forloop.counter
The current iteration, starting at 1.
Example
<ul>
{% for x in fruits %}
<li>{{ forloop.counter }}</li>
{% endfor %}
</ul>
forloop.counter0
The current iteration, starting at 0.
Example
<ul>
{% for x in fruits %}
<li>{{ forloop.counter0 }}</li>
{% endfor %}
</ul>
forloop.first
Allows you to test if the loop is on its first iteration.
Example
<ul>
{% for x in fruits %}
<li
{% if forloop.first %}
style='background-color:lightblue;'
{% endif %}
>{{ x }}</li>
{% endfor %}
</ul>
forloop.last
Allows you to test if the loop is on its last iteration.
Example
<ul>
{% for x in fruits %}
<li
{% if forloop.last %}
style='background-color:lightblue;'
{% endif %}
>{{ x }}</li>
{% endfor %}
</ul>
forloop.revcounter
The current iteration if you start at the end and count backwards, ending up at 1.
Example
<ul>
{% for x in fruits %}
<li>{{ forloop.revcounter }}</li>
{% endfor %}
</ul>
forloop.revcounter0
The current iteration if you start at the end and count backwards, ending up at 0.
Example
<ul>
{% for x in fruits %}
<li>{{ forloop.revcounter0 }}</li>
{% endfor %}
</ul>
