Django provides a few classes that help you manage paginated data – that is, data that’s split across several pages, with “Previous/Next” links. These classes live in django/core/paginator.py.
Paginator class¶Paginator.object_list¶Required. A list, tuple, QuerySet, or other sliceable object with a
count() or __len__() method. For consistent pagination,
QuerySets should be ordered, e.g. with an
order_by() clause or with a default
ordering on the model.
Performance issues paginating large QuerySets
If you’re using a QuerySet with a very large number of items,
requesting high page numbers might be slow on some databases, because
the resulting LIMIT/OFFSET query needs to count the number of
OFFSET records which takes longer as the page number gets higher.
Paginator.per_page¶Required. The maximum number of items to include on a page, not including
orphans (see the orphans optional argument below).
Paginator.orphans¶Optional. Use this when you don’t want to have a last page with very few
items. If the last page would normally have a number of items less than or
equal to orphans, then those items will be added to the previous page
(which becomes the last page) instead of leaving the items on a page by
themselves. For example, with 23 items, per_page=10, and orphans=3,
there will be two pages; the first page with 10 items and the second
(and last) page with 13 items. orphans defaults to zero, which means
pages are never combined and the last page may have one item.
Paginator.allow_empty_first_page¶Optional. Whether or not the first page is allowed to be empty. If
False and object_list is empty, then an EmptyPage error will
be raised.
Paginator.get_page(number)[source]¶Returns a Page object with the given 1-based index, while also
handling out of range and invalid page numbers.
If the page isn’t a number, it returns the first page. If the page number is negative or greater than the number of pages, it returns the last page.
Raises an EmptyPage exception only if you specify
Paginator(..., allow_empty_first_page=False) and the object_list is
empty.
Paginator.page(number)[source]¶Returns a Page object with the given 1-based index. Raises
InvalidPage if the given page number doesn’t exist.
Paginator.count¶The total number of objects, across all pages.
Note
When determining the number of objects contained in object_list,
Paginator will first try calling object_list.count(). If
object_list has no count() method, then Paginator will
fall back to using len(object_list). This allows objects, such as
QuerySet, to use a more efficient count() method when
available.
Paginator.num_pages¶The total number of pages.
Paginator.page_range¶A 1-based range iterator of page numbers, e.g. yielding [1, 2, 3, 4].
Page class¶You usually won’t construct Page objects by hand – you’ll get them using
Paginator.page().
Page(object_list, number, paginator)[source]¶A page acts like a sequence of Page.object_list when using
len() or iterating it directly.
Page.next_page_number()[source]¶Returns the next page number. Raises InvalidPage if next page
doesn’t exist.
Page.previous_page_number()[source]¶Returns the previous page number. Raises InvalidPage if previous
page doesn’t exist.
Page.start_index()[source]¶Returns the 1-based index of the first object on the page, relative to all
of the objects in the paginator’s list. For example, when paginating a list
of 5 objects with 2 objects per page, the second page’s
start_index() would return 3.
Page.end_index()[source]¶Returns the 1-based index of the last object on the page, relative to all
of the objects in the paginator’s list. For example, when paginating a list
of 5 objects with 2 objects per page, the second page’s
end_index() would return 4.
InvalidPage[source]¶A base class for exceptions raised when a paginator is passed an invalid page number.
The Paginator.page() method raises an exception if the requested page is
invalid (i.e. not an integer) or contains no objects. Generally, it’s enough
to catch the InvalidPage exception, but if you’d like more granularity,
you can catch either of the following exceptions:
EmptyPage[source]¶Raised when page() is given a valid value but no objects
exist on that page.
Both of the exceptions are subclasses of InvalidPage, so you can handle
them both with except InvalidPage.
Dec 20, 2019