Fixed #6997 -- Corrected `num_pages` calculation when one item is in the... (96cf3656) · Commits · Dom Sekotill / django

django/core/paginator.py

+9 −5

Original line number	Diff line number	Diff line
		from math import ceil

		class InvalidPage(Exception):
		pass

		@@ -55,13 +57,11 @@ class Paginator(object):
		def _get_num_pages(self):
		"Returns the total number of pages."
		if self._num_pages is None:
		hits = self.count - 1 - self.orphans
		if hits < 1:
		hits = 0
		if hits == 0 and not self.allow_empty_first_page:
		if self.count == 0 and not self.allow_empty_first_page:
		self._num_pages = 0
		else:
		self._num_pages = hits // self.per_page + 1
		hits = max(1, self.count - self.orphans)
		self._num_pages = int(ceil(hits / float(self.per_page)))
		return self._num_pages
		num_pages = property(_get_num_pages)

		@@ -104,6 +104,9 @@ class Page(object):
		Returns the 1-based index of the first object on this page,
		relative to total objects in the paginator.
		"""
		# Special case, return zero if no items.
		if self.paginator.count == 0:
		return 0
		return (self.paginator.per_page * (self.number - 1)) + 1

		def end_index(self):
		@@ -111,6 +114,7 @@ class Page(object):
		Returns the 1-based index of the last object on this page,
		relative to total objects found (hits).
		"""
		# Special case for the last page because there can be orphans.
		if self.number == self.paginator.num_pages:
		return self.paginator.count
		return self.number * self.paginator.per_page

tests/regressiontests/pagination_regress/init.py

0 → 100644

+0 −0

Empty file added.

tests/regressiontests/pagination_regress/models.py

0 → 100644

+1 −0

Original line number	Diff line number	Diff line
		# Models file for tests to run.

tests/regressiontests/pagination_regress/tests.py

0 → 100644

+157 −0

Original line number	Diff line number	Diff line
		from unittest import TestCase

		from django.core.paginator import Paginator, EmptyPage

		class PaginatorTests(TestCase):
		"""
		Tests for the Paginator and Page classes.
		"""

		def check_paginator(self, params, output):
		"""
		Helper method that instantiates a Paginator object from the passed
		params and then checks that it's attributes match the passed output.
		"""
		count, num_pages, page_range = output
		paginator = Paginator(*params)
		self.check_attribute('count', paginator, count, params)
		self.check_attribute('num_pages', paginator, num_pages, params)
		self.check_attribute('page_range', paginator, page_range, params)

		def check_attribute(self, name, paginator, expected, params):
		"""
		Helper method to check a single attribute and gives a nice error
		message upon test failure.
		"""
		got = getattr(paginator, name)
		self.assertEqual(expected, got,
		"For '%s', expected %s but got %s. Paginator parameters were: %s"
		% (name, expected, got, params))

		def test_paginator(self):
		"""
		Tests the paginator attributes using varying inputs.
		"""
		nine = [1, 2, 3, 4, 5, 6, 7, 8, 9]
		ten = nine + [10]
		eleven = ten + [11]
		tests = (
		# Each item is two tuples:
		# First tuple is Paginator parameters - object_list, per_page,
		# orphans, and allow_empty_first_page.
		# Second tuple is resulting Paginator attributes - count,
		# num_pages, and page_range.
		# Ten items, varying orphans, no empty first page.
		((ten, 4, 0, False), (10, 3, [1, 2, 3])),
		((ten, 4, 1, False), (10, 3, [1, 2, 3])),
		((ten, 4, 2, False), (10, 2, [1, 2])),
		((ten, 4, 5, False), (10, 2, [1, 2])),
		((ten, 4, 6, False), (10, 1, [1])),
		# Ten items, varying orphans, allow empty first page.
		((ten, 4, 0, True), (10, 3, [1, 2, 3])),
		((ten, 4, 1, True), (10, 3, [1, 2, 3])),
		((ten, 4, 2, True), (10, 2, [1, 2])),
		((ten, 4, 5, True), (10, 2, [1, 2])),
		((ten, 4, 6, True), (10, 1, [1])),
		# One item, varying orphans, no empty first page.
		(([1], 4, 0, False), (1, 1, [1])),
		(([1], 4, 1, False), (1, 1, [1])),
		(([1], 4, 2, False), (1, 1, [1])),
		# One item, varying orphans, allow empty first page.
		(([1], 4, 0, True), (1, 1, [1])),
		(([1], 4, 1, True), (1, 1, [1])),
		(([1], 4, 2, True), (1, 1, [1])),
		# Zero items, varying orphans, no empty first page.
		(([], 4, 0, False), (0, 0, [])),
		(([], 4, 1, False), (0, 0, [])),
		(([], 4, 2, False), (0, 0, [])),
		# Zero items, varying orphans, allow empty first page.
		(([], 4, 0, True), (0, 1, [1])),
		(([], 4, 1, True), (0, 1, [1])),
		(([], 4, 2, True), (0, 1, [1])),
		# Number if items one less than per_page.
		(([], 1, 0, True), (0, 1, [1])),
		(([], 1, 0, False), (0, 0, [])),
		(([1], 2, 0, True), (1, 1, [1])),
		((nine, 10, 0, True), (9, 1, [1])),
		# Number if items equal to per_page.
		(([1], 1, 0, True), (1, 1, [1])),
		(([1, 2], 2, 0, True), (2, 1, [1])),
		((ten, 10, 0, True), (10, 1, [1])),
		# Number if items one more than per_page.
		(([1, 2], 1, 0, True), (2, 2, [1, 2])),
		(([1, 2, 3], 2, 0, True), (3, 2, [1, 2])),
		((eleven, 10, 0, True), (11, 2, [1, 2])),
		# Number if items one more than per_page with one orphan.
		(([1, 2], 1, 1, True), (2, 1, [1])),
		(([1, 2, 3], 2, 1, True), (3, 1, [1])),
		((eleven, 10, 1, True), (11, 1, [1])),
		)
		for params, output in tests:
		self.check_paginator(params, output)

		def check_indexes(self, params, page_num, indexes):
		"""
		Helper method that instantiates a Paginator object from the passed
		params and then checks that the start and end indexes of for the passed
		page_num match those given as a 2-tuple in indexes.
		"""
		paginator = Paginator(*params)
		if page_num == 'first':
		page_num = 1
		elif page_num == 'last':
		page_num = paginator.num_pages
		page = paginator.page(page_num)
		start, end = indexes
		msg = ("For %s of page %s, expected %s but got %s."
		" Paginator parameters were: %s")
		self.assertEqual(start, page.start_index(),
		msg % ('start index', page_num, start, page.start_index(), params))
		self.assertEqual(end, page.end_index(),
		msg % ('end index', page_num, end, page.end_index(), params))

		def test_page_indexes(self):
		"""
		Tests that paginator pages have the correct start and end indexes.
		"""
		ten = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
		tests = (
		# Each item is three tuples:
		# First tuple is Paginator parameters - object_list, per_page,
		# orphans, and allow_empty_first_page.
		# Second tuple is the start and end indexes of the first page.
		# Third tuple is the start and end indexes of the last page.
		# Ten items, varying per_page, no orphans.
		((ten, 1, 0, True), (1, 1), (10, 10)),
		((ten, 2, 0, True), (1, 2), (9, 10)),
		((ten, 3, 0, True), (1, 3), (10, 10)),
		((ten, 5, 0, True), (1, 5), (6, 10)),
		# Ten items, varying per_page, with orphans.
		((ten, 1, 1, True), (1, 1), (9, 10)),
		((ten, 1, 2, True), (1, 1), (8, 10)),
		((ten, 3, 1, True), (1, 3), (7, 10)),
		((ten, 3, 2, True), (1, 3), (7, 10)),
		((ten, 3, 4, True), (1, 3), (4, 10)),
		((ten, 5, 1, True), (1, 5), (6, 10)),
		((ten, 5, 2, True), (1, 5), (6, 10)),
		((ten, 5, 5, True), (1, 10), (1, 10)),
		# One item, varying orphans, no empty first page.
		(([1], 4, 0, False), (1, 1), (1, 1)),
		(([1], 4, 1, False), (1, 1), (1, 1)),
		(([1], 4, 2, False), (1, 1), (1, 1)),
		# One item, varying orphans, allow empty first page.
		(([1], 4, 0, True), (1, 1), (1, 1)),
		(([1], 4, 1, True), (1, 1), (1, 1)),
		(([1], 4, 2, True), (1, 1), (1, 1)),
		# Zero items, varying orphans, allow empty first page.
		(([], 4, 0, True), (0, 0), (0, 0)),
		(([], 4, 1, True), (0, 0), (0, 0)),
		(([], 4, 2, True), (0, 0), (0, 0)),
		)
		for params, first, last in tests:
		self.check_indexes(params, 'first', first)
		self.check_indexes(params, 'last', last)
		# When no items and no empty first page, we should get EmptyPage error.
		self.assertRaises(EmptyPage, self.check_indexes, ([], 4, 0, False), 1, None)
		self.assertRaises(EmptyPage, self.check_indexes, ([], 4, 1, False), 1, None)
		self.assertRaises(EmptyPage, self.check_indexes, ([], 4, 2, False), 1, None)