========= Paginator ========= 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 :source:`django/core/paginator.py`. For examples, see the :doc:`Pagination topic guide `. .. module:: django.core.paginator :synopsis: Classes to help you easily manage paginated data. ``Paginator`` class =================== .. class:: Paginator(object_list, per_page, orphans=0, allow_empty_first_page=True, error_messages=None) A paginator acts like a sequence of :class:`Page` when using ``len()`` or iterating it directly. .. attribute:: Paginator.object_list Required. A list, tuple, ``QuerySet``, or other sliceable object with a ``count()`` or ``__len__()`` method. For consistent pagination, ``QuerySet``\s should be ordered, e.g. with an :meth:`~django.db.models.query.QuerySet.order_by` clause or with a default :attr:`~django.db.models.Options.ordering` on the model. .. admonition:: Performance issues paginating large ``QuerySet``\s 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. .. attribute:: Paginator.per_page Required. The maximum number of items to include on a page, not including orphans (see the :attr:`~Paginator.orphans` optional argument below). .. attribute:: 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. .. attribute:: 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. .. attribute:: Paginator.error_messages .. versionadded:: 5.0 The ``error_messages`` argument lets you override the default messages that the paginator will raise. Pass in a dictionary with keys matching the error messages you want to override. Available error message keys are: ``invalid_page``, ``min_page``, and ``no_results``. For example, here is the default error message: .. code-block:: pycon >>> from django.core.paginator import Paginator >>> paginator = Paginator([1, 2, 3], 2) >>> paginator.page(5) Traceback (most recent call last): ... EmptyPage: That page contains no results And here is a custom error message: .. code-block:: pycon >>> paginator = Paginator( ... [1, 2, 3], ... 2, ... error_messages={"no_results": "Page does not exist"}, ... ) >>> paginator.page(5) Traceback (most recent call last): ... EmptyPage: Page does not exist Methods ------- .. method:: Paginator.get_page(number) Returns a :class:`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 :exc:`EmptyPage` exception only if you specify ``Paginator(..., allow_empty_first_page=False)`` and the ``object_list`` is empty. .. method:: Paginator.page(number) Returns a :class:`Page` object with the given 1-based index. Raises :exc:`PageNotAnInteger` if the ``number`` cannot be converted to an integer by calling ``int()``. Raises :exc:`EmptyPage` if the given page number doesn't exist. .. method:: Paginator.get_elided_page_range(number, *, on_each_side=3, on_ends=2) Returns a 1-based list of page numbers similar to :attr:`Paginator.page_range`, but may add an ellipsis to either or both sides of the current page number when :attr:`Paginator.num_pages` is large. The number of pages to include on each side of the current page number is determined by the ``on_each_side`` argument which defaults to 3. The number of pages to include at the beginning and end of page range is determined by the ``on_ends`` argument which defaults to 2. For example, with the default values for ``on_each_side`` and ``on_ends``, if the current page is 10 and there are 50 pages, the page range will be ``[1, 2, '…', 7, 8, 9, 10, 11, 12, 13, '…', 49, 50]``. This will result in pages 7, 8, and 9 to the left of and 11, 12, and 13 to the right of the current page as well as pages 1 and 2 at the start and 49 and 50 at the end. Raises :exc:`InvalidPage` if the given page number doesn't exist. Attributes ---------- .. attribute:: Paginator.ELLIPSIS A translatable string used as a substitute for elided page numbers in the page range returned by :meth:`~Paginator.get_elided_page_range`. Default is ``'…'``. .. attribute:: 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. .. attribute:: Paginator.num_pages The total number of pages. .. attribute:: 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 by iterating :class:`Paginator`, or by using :meth:`Paginator.page`. .. class:: Page(object_list, number, paginator) A page acts like a sequence of :attr:`Page.object_list` when using ``len()`` or iterating it directly. Methods ------- .. method:: Page.has_next() Returns ``True`` if there's a next page. .. method:: Page.has_previous() Returns ``True`` if there's a previous page. .. method:: Page.has_other_pages() Returns ``True`` if there's a next **or** previous page. .. method:: Page.next_page_number() Returns the next page number. Raises :exc:`InvalidPage` if next page doesn't exist. .. method:: Page.previous_page_number() Returns the previous page number. Raises :exc:`InvalidPage` if previous page doesn't exist. .. method:: Page.start_index() 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 :meth:`~Page.start_index` would return ``3``. .. method:: Page.end_index() 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 :meth:`~Page.end_index` would return ``4``. Attributes ---------- .. attribute:: Page.object_list The list of objects on this page. .. attribute:: Page.number The 1-based page number for this page. .. attribute:: Page.paginator The associated :class:`Paginator` object. Exceptions ========== .. exception:: InvalidPage A base class for exceptions raised when a paginator is passed an invalid page number. The :meth:`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: .. exception:: PageNotAnInteger Raised when :meth:`~Paginator.page` is given a value that isn't an integer. .. exception:: EmptyPage Raised when :meth:`~Paginator.page` is given a valid value but no objects exist on that page. Both of the exceptions are subclasses of :exc:`InvalidPage`, so you can handle them both with ``except InvalidPage``.