1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
.. _topics-pagination:
==========
Pagination
==========
.. module:: django.core.paginator
:synopsis: Classes to help you easily manage paginated data.
.. versionchanged:: 1.0
Pagination facilities have been almost fully reworked.
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 :file:`django/core/paginator.py`.
Example
=======
Give :class:`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
>>> p.page_range
[1, 2]
>>> 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()
3
>>> 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
.. note::
Note that you can give ``Paginator`` a list/tuple, a Django ``QuerySet``, or
any other object with a ``count()`` or ``__len__()`` method. When
determining the number of objects contained in the passed object,
``Paginator`` will first try calling ``count()``, then fallback to using
``len()`` if the passed object has no ``count()`` method. This allows
objects such as Django's ``QuerySet`` to use a more efficient ``count()``
method when available.
``Paginator`` objects
=====================
The :class:`Paginator` class has this constructor:
.. class:: Paginator(object_list, per_page, orphans=0, allow_empty_first_page=True)
Required arguments
------------------
``object_list``
A list, tuple, Django ``QuerySet``, or other sliceable object with a
``count()`` or ``__len__()`` method.
``per_page``
The maximum number of items to include on a page, not including orphans
(see the ``orphans`` optional argument below).
Optional arguments
------------------
``orphans``
The minimum number of items allowed on the last page, defaults to zero.
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.
``allow_empty_first_page``
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.
Methods
-------
.. method:: Paginator.page(number)
Returns a :class:`Page` object with the given 1-based index. Raises
:exc:`InvalidPage` if the given page number doesn't exist.
Attributes
----------
.. 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
fallback to using ``object_list.__len__()``. This allows objects, such
as Django's ``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 of page numbers, e.g., ``[1, 2, 3, 4]``.
``InvalidPage`` exceptions
==========================
The ``page()`` method raises ``InvalidPage`` if the requested page is invalid
(i.e., not an integer) or contains no objects. Generally, it's enough to trap
the ``InvalidPage`` exception, but if you'd like more granularity, you can trap
either of the following exceptions:
``PageNotAnInteger``
Raised when ``page()`` is given a value that isn't an integer.
``EmptyPage``
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 a simple ``except InvalidPage``.
``Page`` objects
================
.. class:: Page(object_list, number, paginator):
You usually won't construct :class:`Pages <Page>` by hand -- you'll get them
using :meth:`Paginator.page`.
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. Note that this is "dumb" and will return the
next page number regardless of whether a subsequent page exists.
.. method:: Page.previous_page_number()
Returns the previous page number. Note that this is "dumb" and will return
the previous page number regardless of whether a previous page exists.
.. 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.
|
