Django实现翻页的示例代码

Django提供了翻页器。用Django的Paginator类实现

一、views模块导入Paginator类实现数据分页

ApiTest/apiviews.py

每行都加了注释，希望有助于理解。

from django.shortcuts import render
from ApiTest.models import ApiTest
from django.contrib.auth.decorators import login_required
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger, InvalidPage

@login_required
def api_test_manage(request):
   username = request.session.get('user', '')
   # 获取所有接口测试数据
   apitest_list = ApiTest.objects.all().order_by('id')
   # 生成Paginator对象对数据分页，每页显示10条数据
   paginator = Paginator(apitest_list,10)
   # 使用request.GET.get()函数获取url中的page参数的数值。默认第1页
   page = request.GET.get('page', 1)
   # 把获取的当前页码数转换成整数类型
   current_page = int(page)
   try:
    # 获取查询页数的接口数据列表，page()函数会判断page实参是否是有效数字。page()函数源码附在文章的最后
       apitest_list = paginator.page(page)
   except PageNotAnInteger:
       apitest_list = paginator.page(1)
   except (EmptyPage, InvalidPage):
    # paginator.num_pages
       apitest_list = paginator.page(paginator.num_pages)
   return render(request, "apitest_manage.html", {'user': username, 'apitests': apitest_list})

二、将views的数据渲染到前端模板上

在对应的html文件中加入此段代码即可。

<div class="container">
   <ul class="pagination" id="pager">
       {# 上一页链接 #}
       {％ if apitests.has_previous ％}
       <li class="previous"><a href="/apitest_manage/?page={{ apitests.previous_page_number }}" rel="external nofollow" >上一页</a></li>
       {％ else ％}
       <li class="previous disabled"><a href="#" rel="external nofollow"  rel="external nofollow" >上一页</a></li>
       {％ endif ％}

{# 中间数字显示 #}
       {％  for num in apitests.paginator.page_range ％}
           {％  if num == currentPage ％}
               <li class="item active"><a href="/apitest_manage/?page={{ num }}" rel="external nofollow"  rel="external nofollow" >{{ num }}</a></li>
           {％ else ％}
               <li class="item"><a href="/apitest_manage/?page={{ num }}" rel="external nofollow"  rel="external nofollow" >{{ num }}</a></li>
           {％ endif ％}
       {％ endfor ％}

{# 下一页链接 #}
       {％ if apitests.has_next ％}   {# 如果有下一页，则正常显示下一页链接 #}
           <li class="next"><a href="/apitest_manage/?page={{ apitests.next_page_number }}" rel="external nofollow" >下一页</a></li>
       {％ else ％}
           <li class="next disabled"><a href="#" rel="external nofollow"  rel="external nofollow" >下一页</a></li>
       {％ endif ％}

</ul>
</div>

三、效果展示

四、Paginator类源码

此类主要用在views文件

class Paginator:
   def __init__(self, object_list, per_page, orphans=0,
                allow_empty_first_page=True):
       self.object_list = object_list
       self._check_object_list_is_ordered()
       self.per_page = int(per_page)
       self.orphans = int(orphans)
       self.allow_empty_first_page = allow_empty_first_page

def validate_number(self, number):
       """Validate the given 1-based page number."""
       try:
           if isinstance(number, float) and not number.is_integer():
               raise ValueError
           number = int(number)
       except (TypeError, ValueError):
           raise PageNotAnInteger(_('That page number is not an integer'))
       if number < 1:
           raise EmptyPage(_('That page number is less than 1'))
       if number > self.num_pages:
           if number == 1 and self.allow_empty_first_page:
               pass
           else:
               raise EmptyPage(_('That page contains no results'))
       return number

def get_page(self, number):
       """
       Return a valid page, even if the page argument isn't a number or isn't
       in range.
       """
       try:
           number = self.validate_number(number)
       except PageNotAnInteger:
           number = 1
       except EmptyPage:
           number = self.num_pages
       return self.page(number)

def page(self, number):
       """Return a Page object for the given 1-based page number."""
       number = self.validate_number(number)
       bottom = (number - 1) * self.per_page
       top = bottom + self.per_page
       if top + self.orphans >= self.count:
           top = self.count
       return self._get_page(self.object_list[bottom:top], number, self)

def _get_page(self, *args, **kwargs):
       """
       Return an instance of a single page.

This hook can be used by subclasses to use an alternative to the
       standard :cls:`Page` object.
       """
       return Page(*args, **kwargs)

@cached_property
   def count(self):
       """Return the total number of objects, across all pages."""
       c = getattr(self.object_list, 'count', None)
       if callable(c) and not inspect.isbuiltin(c) and method_has_no_args(c):
           return c()
       return len(self.object_list)

@cached_property
   def num_pages(self):
       """Return the total number of pages."""
       if self.count == 0 and not self.allow_empty_first_page:
           return 0
       hits = max(1, self.count - self.orphans)
       return ceil(hits / self.per_page)

@property
   def page_range(self):
       """
       Return a 1-based range of pages for iterating through within
       a template for loop.
       """
       return range(1, self.num_pages + 1)

def _check_object_list_is_ordered(self):
       """
       Warn if self.object_list is unordered (typically a QuerySet).
       """
       ordered = getattr(self.object_list, 'ordered', None)
       if ordered is not None and not ordered:
           obj_list_repr = (
               '{} {}'.format(self.object_list.model, self.object_list.__class__.__name__)
               if hasattr(self.object_list, 'model')
               else '{!r}'.format(self.object_list)
           )
           warnings.warn(
               'Pagination may yield inconsistent results with an unordered '
               'object_list: {}.'.format(obj_list_repr),
               UnorderedObjectListWarning,
               stacklevel=3
           )

五、Page类源码

此类主要用在html文件

class Page(collections.abc.Sequence):

def __init__(self, object_list, number, paginator):
       self.object_list = object_list
       self.number = number
       self.paginator = paginator

def __repr__(self):
       return '<Page ％s of ％s>' ％ (self.number, self.paginator.num_pages)

def __len__(self):
       return len(self.object_list)

def __getitem__(self, index):
       if not isinstance(index, (int, slice)):
           raise TypeError(
               'Page indices must be integers or slices, not ％s.'
               ％ type(index).__name__
           )
       # The object_list is converted to a list so that if it was a QuerySet
       # it won't be a database hit per __getitem__.
       if not isinstance(self.object_list, list):
           self.object_list = list(self.object_list)
       return self.object_list[index]

def has_next(self):
       return self.number < self.paginator.num_pages

def has_previous(self):
       return self.number > 1

def has_other_pages(self):
       return self.has_previous() or self.has_next()

def next_page_number(self):
       return self.paginator.validate_number(self.number + 1)

def previous_page_number(self):
       return self.paginator.validate_number(self.number - 1)

def start_index(self):
       """
       Return 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):
       """
       Return 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

来源：https://blog.csdn.net/weixin_38851970/article/details/107554847