Постраничный вывод

Django provides high-level and low-level ways to help you manage paginated data – that is, data that’s split across several pages, with «Previous/Next» links.

The Paginator class

Under the hood, all methods of pagination use the Paginator class. It does all the heavy lifting of actually splitting a QuerySet into Page objects.

Пример

Give Paginator a list of objects, plus the number of items you’d like to have on each page, and it gives you methods for accessing the items for each page:

>>> from django.core.paginator import Paginator
>>> objects = ['john', 'paul', 'george', 'ringo']
>>> p = Paginator(objects, 2)

>>> p.count
4
>>> p.num_pages
2
>>> type(p.page_range)
<class 'range_iterator'>
>>> p.page_range
range(1, 3)

>>> page1 = p.page(1)
>>> page1
<Page 1 of 2>
>>> page1.object_list
['john', 'paul']

>>> page2 = p.page(2)
>>> page2.object_list
['george', 'ringo']
>>> page2.has_next()
False
>>> page2.has_previous()
True
>>> page2.has_other_pages()
True
>>> page2.next_page_number()
Traceback (most recent call last):
...
EmptyPage: That page contains no results
>>> page2.previous_page_number()
1
>>> page2.start_index() # The 1-based index of the first item on this page
3
>>> page2.end_index() # The 1-based index of the last item on this page
4

>>> p.page(0)
Traceback (most recent call last):
...
EmptyPage: That page number is less than 1
>>> p.page(3)
Traceback (most recent call last):
...
EmptyPage: That page contains no results

Примечание

Следует отметить, что вы можете передать классу Paginator список/кортеж, QuerySet Django или любой другой объект, который имеет методы count() или __len__(). Для определения количества объектов, содержащихся в переданном объекте, Paginator сначала попробует вызвать метод count(), затем, при его отсутствии, вызывает len(). Такой подход позволяет объектам, подобным QuerySet, более эффективно использовать метод count() при его наличии.

Paginating a ListView

django.views.generic.list.ListView provides a builtin way to paginate the displayed list. You can do this by adding a paginate_by attribute to your view class, for example:

from django.views.generic import ListView

from myapp.models import Contact

class ContactList(ListView):
    paginate_by = 2
    model = Contact

This limits the number of objects per page and adds a paginator and page_obj to the context. To allow your users to navigate between pages, add links to the next and previous page, in your template like this:

{% for contact in page_obj %}
    {# Each "contact" is a Contact model object. #}
    {{ contact.full_name|upper }}<br>
    ...
{% endfor %}

<div class="pagination">
    <span class="step-links">
        {% if page_obj.has_previous %}
            <a href="?page=1">&laquo; first</a>
            <a href="?page={{ page_obj.previous_page_number }}">previous</a>
        {% endif %}

        <span class="current">
            Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}.
        </span>

        {% if page_obj.has_next %}
            <a href="?page={{ page_obj.next_page_number }}">next</a>
            <a href="?page={{ page_obj.paginator.num_pages }}">last &raquo;</a>
        {% endif %}
    </span>
</div>

Using Paginator in a view function

Here’s an example using Paginator in a view function to paginate a queryset:

from django.core.paginator import Paginator
from django.shortcuts import render

from myapp.models import Contact

def listing(request):
    contact_list = Contact.objects.all()
    paginator = Paginator(contact_list, 25) # Show 25 contacts per page.

    page_number = request.GET.get('page')
    page_obj = paginator.get_page(page_number)
    return render(request, 'list.html', {'page_obj': page_obj})

In the template list.html, you can include navigation between pages in the same way as in the template for the ListView above.