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  • django分页

    一、Django的内置分页器(paginator)

    1.1 内置方法和属性

    from django.core.paginator import Paginator
    Paginator对象:    paginator = Paginator(user_list, 10)
    # per_page: 每页显示条目数量
    # count:    数据总个数
    # num_pages:总页数
    # page_range:总页数的索引范围,如: (1,10),(1,200)
    # page:     page对象    
    page对象:page=paginator.page(1)
    # has_next              是否有下一页
    # next_page_number      下一页页码
    # has_previous          是否有上一页
    # previous_page_number  上一页页码
    # object_list           分页之后的数据列表
    # number                当前页
    # paginator             paginator对象

    1. 2 应用View层

    from django.shortcuts import render,HttpResponse
    
    # Create your views here.
    from app01.models import *
    from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
    
    def index(request):
    
        '''
        批量导入数据:
    
        Booklist=[]
        for i in range(100):
            Booklist.append(Book(title="book"+str(i),price=30+i*i))
        Book.objects.bulk_create(Booklist)
        '''
    
        '''
    分页器的使用:
    
        book_list=Book.objects.all()
    
        paginator = Paginator(book_list, 10)
    
        print("count:",paginator.count)           #数据总数
        print("num_pages",paginator.num_pages)    #总页数
        print("page_range",paginator.page_range)  #页码的列表
    
    
    
        page1=paginator.page(1) #第1页的page对象
        for i in page1:         #遍历第1页的所有数据对象
            print(i)
    
        print(page1.object_list) #第1页的所有数据
    
    
        page2=paginator.page(2)
    
        print(page2.has_next())            #是否有下一页
        print(page2.next_page_number())    #下一页的页码
        print(page2.has_previous())        #是否有上一页
        print(page2.previous_page_number()) #上一页的页码
    
    
    
        # 抛错
        #page=paginator.page(12)   # error:EmptyPage 超过页码范围
    
        #page=paginator.page("z")   # error:PageNotAnInteger 非法页码值
      
        #page = page_obj.page(-1)  #That page number is less than 1 ,也是EmptyPage的错误,页码不能为负数,最少也是1
        '''
    
    
        book_list=Book.objects.all()
    
        paginator = Paginator(book_list, 10) #按照每页显示10条来计算
        page = request.GET.get('page',1)  #将来访问的url是这样的 http://127.0.0.1:8000/路径/?page=1,第一次访问时默认给1
        currentPage=int(page)
    
    
        try:
            print(page)
            book_list = paginator.page(page)
        except PageNotAnInteger:
            book_list = paginator.page(1)
        except EmptyPage:
            book_list = paginator.page(paginator.num_pages)
    
    
        return render(request,"index.html",{"book_list":book_list,"paginator":paginator,"currentPage":currentPage})

    1. 3 模版层 index.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css"     integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
    </head>
    <body>
    
    <div class="container">
    
        <h4>分页器</h4>
        <ul>
    
            {% for book in book_list %}
                 <li>{{ book.title }} -----{{ book.price }}</li>
            {% endfor %}
    
         </ul>
    
    
        <ul class="pagination" id="pager">
    
                     {% if book_list.has_previous %}
                        <li class="previous"><a href="/index/?page={{ book_list.previous_page_number }}">上一页</a></li>
                     {% else %}
                        <li class="previous disabled"><a href="#">上一页</a></li>
                     {% endif %}
    
    
                     {% for num in paginator.page_range %}
    
                         {% if num == currentPage %}
                           <li class="item active"><a href="/index/?page={{ num }}">{{ num }}</a></li>
                         {% else %}
                           <li class="item"><a href="/index/?page={{ num }}">{{ num }}</a></li>
    
                         {% endif %}
                     {% endfor %}
    
    
    
                     {% if book_list.has_next %}
                        <li class="next"><a href="/index/?page={{ book_list.next_page_number }}">下一页</a></li>
                     {% else %}
                        <li class="next disabled"><a href="#">下一页</a></li>
                     {% endif %}
    
                </ul>
    </div>
    
    
    </body>
    </html>

    1. 4 扩展

    '''
        显示左5,右5,总共11个页,
        1 如果总页码大于11
            1.1 if 当前页码减5小于1,要生成1到12的列表(顾头不顾尾,共11个页码)
                page_range=range(1,12)
            1.2 elif 当前页码+5大于总页码,生成当前页码减10,到当前页码加1的列表(顾头不顾尾,共11个页码)
                page_range=range(paginator.num_pages-10,paginator.num_pages+1)
            1.3 else 生成当前页码-5,到当前页码+6的列表
                page_range=range(current_page_num-5,current_page_num+6)
        2 其它情况,生成的列表就是pageinator的page_range
            page_range=paginator.page_range
    
        '''
    from django.core.paginator import Paginator,PageNotAnInteger,EmptyPage
    def show(request):
    
        book_objs = models.Book.objects.all()
        page_obj = Paginator(book_objs,1)
        print('数据总数',page_obj.count)
        print('总页数',page_obj.num_pages)
        print('页码列表',page_obj.page_range)
    
        page1 = page_obj.page(1)
        for i in page1:
            print(i)
        print(page1.object_list)
        page2 = page_obj.page(2)
    
        print(page2.has_previous())
        print(page2.has_next())
        print(page2.next_page_number())
        print(page2.previous_page_number())
        # page = page_obj.page(-1)
        page_num = request.GET.get('page',1)
    
        try:
            current_page_num = int(page_num)
            page_num_data = page_obj.page(current_page_num)
        except PageNotAnInteger:
            current_page_num = 1
            page_num_data = page_obj.page(current_page_num)
        except EmptyPage:
            current_page_num = page_obj.num_pages
            page_num_data = page_obj.page(current_page_num)
        except Exception:
            current_page_num = 1
            page_num_data = page_obj.page(current_page_num)
        if page_obj.num_pages > 11:  #扩展,如果总的页码数大于了11,我们就不把所有的页码数显示出来了,只显示其中11个页面,当前页左边5个,右边5个
            if current_page_num - 5 < 1:  
                pageRange = range(1,12)
            elif current_page_num + 5 > page_obj.num_pages:
                pageRange = range(page_obj.num_pages-10,page_obj.num_pages+1)
            else:
                pageRange = range(current_page_num - 5,current_page_num + 6)
    
        else:
            pageRange = page_obj.page_range
    
        book_objs = page_num_data
        return render(request,'show.html',{'book_objs':book_objs,'current_page_num':current_page_num,'page_obj':page_obj,'pageRange':pageRange})
    {% load static %}
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <link rel="stylesheet" href="{% static 'bootstrap-3.3.0-dist/dist/css/bootstrap.min.css' %}">
    </head>
    <body>
    
    <h1>数据展示</h1>
    <div class="container-fluid">
        <div class="row">
            <div class="col-md-6 col-md-offset-3">
                <table class="table">
                    <thead>
                        <tr>
                            <th>id</th>
                            <th>title</th>
                            <th>价格</th>
                            <th>性别</th>
                            <th>出版日期</th>
                            <th>出版社</th>
                            <th>作者</th>
                            <th>操作</th>
                        </tr>
                    </thead>
                    <tbody>
                        {% for book_obj in book_objs %}
                             <tr>
                                <td>{{ book_obj.pk }}</td>
                                <td>{{ book_obj.title }}</td>
                                <td>{{ book_obj.price }}</td>
                                <td>{{ book_obj.get_sex_display }}</td>
                                <td>{{ book_obj.publishDate|date:'Y-d-m' }}</td>
                                <td>{{ book_obj.publish.name }}</td>
                                <td>
                                    {% for author in book_obj.authors.all %}
                                        {{ author.name }}
                                    {% endfor %}
    
                                </td>
                                <td>
                                    <a class="btn btn-warning" href="{% url 'edit_book' book_obj.pk  %}">编辑</a>
                                    <a class="btn btn-danger" href="{% url 'delete_book' book_obj.pk  %}">删除</a>
                                </td>
                             </tr>
                        {% endfor %}
                    </tbody>
                </table>
                <ul class="pagination" id="pager">
                    {% if book_objs.has_previous %}
                    <li class="previous"><a href="/show/?page={{ book_objs.previous_page_number }}">上一页</a></li>
                    {% else %}
                    <li class="previous disabled"><a href="javascript:void(0)">上一页</a></li>
                    {% endif %}
                    <!--{% for num in page_obj.page_range %}-->
                    {% for num in pageRange %}
                        {% if num == current_page_num %}
                         <li class="item active"><a href="/show/?page={{ num }}">{{ num }}</a></li>
                        {% else %}
                           <li class="item"><a href="/show/?page={{ num }}">{{ num }}</a></li>
    
                         {% endif %}
    
                    {% endfor %}
                    {% if book_objs.has_next %}
                        <li class="next"><a href="/show/?page={{ book_objs.next_page_number }}">下一页</a></li>
                     {% else %}
                        <li class="next disabled"><a href="#">下一页</a></li>
                     {% endif %}
    
                </ul>
            </div>
        </div>
    
    </div>
    
    </body>
    <script src="{% static 'bootstrap-3.3.0-dist/dist/jQuery/jquery-3.1.1.js' %}"></script>
    <script src="{% static 'bootstrap-3.3.0-dist/dist/js/bootstrap.min.js' %}"></script>
    </html>

    model.py

    from django.db import models
    
    # Create your models here.
    
    
    class Author(models.Model):
        nid = models.AutoField(primary_key=True)
        name=models.CharField( max_length=32)
        age=models.IntegerField()
        authorDetail=models.OneToOneField(to="AuthorDetail",to_field="nid")
        def __str__(self):
            return self.name
    class AuthorDetail(models.Model):
    
        nid = models.AutoField(primary_key=True)
        birthday=models.DateField()
        telephone=models.BigIntegerField()
        addr=models.CharField( max_length=64)
    
    class Publish(models.Model):
        nid = models.AutoField(primary_key=True)
        name=models.CharField( max_length=32)
        city=models.CharField( max_length=32)
        email=models.EmailField()
        def __str__(self):
            return self.name
    
    class Book(models.Model):
    
        nid = models.AutoField(primary_key=True)
        title = models.CharField( max_length=32)
    
        publishDate=models.DateField()
        price=models.DecimalField(max_digits=5,decimal_places=2)
        publish=models.ForeignKey(to="Publish",to_field="nid")
        authors=models.ManyToManyField(to='Author',)
        def __str__(self):
            return self.title

     二、自定义分页

    from django.utils.safestring import mark_safe #将字符穿转化为标签或者在前端用safe

     准备工作

    我们使用脚本批量创建一些测试数据(将下面的代码保存到bulk_create.py文件中放到Django项目的根目录,直接执行即可。):

    import os
    
    if __name__ == "__main__":
        os.environ.setdefault("DJANGO_SETTINGS_MODULE", "about_orm.settings")
    
        import django
        django.setup()
    
        from app01 import models
        bulk_obj = (models.Publisher(name='第{}出版社'.format(i)) for i in range(300))
        models.Publisher.objects.bulk_create(bulk_obj) #批量添加,注意写法

    看下面几个版本的分页:

    也可把获取的分页数据装入迭代器中,传入前端循环

    def publisher_list(request):
        # 从URL中取当前访问的页码数
        try:
            current_page = int(request.GET.get('page'))
        except Exception as e:
            # 取不到或者页码数不是数字都默认展示第1页
            current_page = 1
        # 总数据量
        total_count = models.Publisher.objects.count()
        # 定义每页显示多少条数据
        per_page = 10
        # 计算出总页码数
        total_page, more = divmod(total_count, per_page)
        if more:
            total_page += 1
        # 定义页面上最多显示多少页码(为了左右对称,一般设为奇数)
        max_show = 11
        half_show = max_show // 2
        # 计算一下页面显示的页码范围
        if total_page <= max_show:  # 总页码数小于最大显示页码数
            page_start = 1
            page_end = total_page
        elif current_page + half_show >= total_page:  # 右边越界
            page_end = total_page
            page_start = total_page - max_show
        elif current_page - half_show <= 1:  # 左边越界
            page_start = 1
            page_end = max_show
        else:  # 正常页码区间
            page_start = current_page - half_show
            page_end = current_page + half_show
        # 数据索引起始位置
        data_start = (current_page-1) * per_page
        data_end = current_page * per_page
    
        publisher_list = models.Publisher.objects.all()[data_start:data_end]
    
        # 生成页面上显示的页码
        page_html_list = []
        page_html_list.append('<nav aria-label="Page navigation"><ul class="pagination">')
        # 加首页
        first_li = '<li><a href="/publisher_list/?page=1">首页</a></li>'
        page_html_list.append(first_li)
        # 加上一页
        if current_page == 1:
            prev_li = '<li><a href="#"><span aria-hidden="true">&laquo;</span></a></li>'
        else:
            prev_li = '<li><a href="/publisher_list/?page={}"><span aria-hidden="true">&laquo;</span></a></li>'.format(current_page - 1)
        page_html_list.append(prev_li)
        for i in range(page_start, page_end + 1):
            if i == current_page:
                li_tag = '<li class="active"><a href="/publisher_list/?page={0}">{0}</a></li>'.format(i)
            else:
                li_tag = '<li><a href="/publisher_list/?page={0}">{0}</a></li>'.format(i)
            page_html_list.append(li_tag)
        # 加下一页
        if current_page == total_page:
            next_li = '<li><a href="#"><span aria-hidden="true">&raquo;</span></a></li>'
        else:
            next_li = '<li><a href="/publisher_list/?page={}"><span aria-hidden="true">&raquo;</span></a></li>'.format(current_page + 1)
        page_html_list.append(next_li)
        # 加尾页
        page_end_li = '<li><a href="/publisher_list/?page={}">尾页</a></li>'.format(total_page)
        page_html_list.append(page_end_li)
        page_html_list.append('</ul></nav>')
        page_html = "".join(page_html_list)
        return render(request, "publisher_list.html", {"publisher_list": publisher_list, "page_html": page_html})
    第一个版本

     第二个版本

    class Pagination(object):
        """自定义分页(Bootstrap版)"""
        def __init__(self, current_page, total_count, base_url, per_page=10, max_show=11):
            """
            :param current_page: 当前请求的页码
            :param total_count: 总数据量
            :param base_url: 请求的URL
            :param per_page: 每页显示的数据量,默认值为10
            :param max_show: 页面上最多显示多少个页码,默认值为11
            """
            try:
                self.current_page = int(current_page)
            except Exception as e:
                # 取不到或者页码数不是数字都默认展示第1页
                self.current_page = 1
            # 定义每页显示多少条数据
            self.per_page = per_page
            # 计算出总页码数
            total_page, more = divmod(total_count, per_page)
            if more:
                total_page += 1
            self.total_page = total_page
            # 定义页面上最多显示多少页码(为了左右对称,一般设为奇数)
            self.max_show = max_show
            self.half_show = max_show // 2
            self.base_url = base_url
    
        @property
        def start(self):
            return (self.current_page-1) * self.per_page
    
        @property
        def end(self):
            return self.current_page * self.per_page
    
        def page_html(self):
            # 计算一下页面显示的页码范围
            if self.total_page <= self.max_show:  # 总页码数小于最大显示页码数
                page_start = 1
                page_end = self.total_page
            elif self.current_page + self.half_show >= self.total_page:  # 右边越界
                page_end = self.total_page
                page_start = self.total_page - self.max_show
            elif self.current_page - self.half_show <= 1:  # 左边越界
                page_start = 1
                page_end = self.max_show
            else:  # 正常页码区间
                page_start = self.current_page - self.half_show
                page_end = self.current_page + self.half_show
            # 生成页面上显示的页码
            page_html_list = []
            page_html_list.append('<nav aria-label="Page navigation"><ul class="pagination">')
            # 加首页
            first_li = '<li><a href="{}?page=1">首页</a></li>'.format(self.base_url)
            page_html_list.append(first_li)
            # 加上一页
            if self.current_page == 1:
                prev_li = '<li><a href="#"><span aria-hidden="true">&laquo;</span></a></li>'
            else:
                prev_li = '<li><a href="{}?page={}"><span aria-hidden="true">&laquo;</span></a></li>'.format(
                    self.base_url, self.current_page - 1)
            page_html_list.append(prev_li)
            for i in range(page_start, page_end + 1):
                if i == self.current_page:
                    li_tag = '<li class="active"><a href="{0}?page={1}">{1}</a></li>'.format(self.base_url, i)
                else:
                    li_tag = '<li><a href="{0}?page={1}">{1}</a></li>'.format(self.base_url, i)
                page_html_list.append(li_tag)
            # 加下一页
            if self.current_page == self.total_page:
                next_li = '<li><a href="#"><span aria-hidden="true">&raquo;</span></a></li>'
            else:
                next_li = '<li><a href="{}?page={}"><span aria-hidden="true">&raquo;</span></a></li>'.format(
                    self.base_url, self.current_page + 1)
            page_html_list.append(next_li)
            # 加尾页
            page_end_li = '<li><a href="{}?page={}">尾页</a></li>'.format(self.base_url, self.total_page)
            page_html_list.append(page_end_li)
            page_html_list.append('</ul></nav>')
            return "".join(page_html_list)
    封装保存版
    def publisher_list(request):
        # 从URL中取当前访问的页码数
        current_page = int(request.GET.get('page'))
        # 比len(models.Publisher.objects.all())更高效
        total_count = models.Publisher.objects.count()
        page_obj = Pagination(current_page, total_count, request.path_info)
        data = models.Publisher.objects.all()[page_obj.start:page_obj.end]
        page_html = page_obj.page_html()
        return render(request, "publisher_list.html", {"publisher_list": data, "page_html": page_html})
    使用示例

    再来一版django内置分页器的分页

    from django.shortcuts import render
    from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
    
    L = []
    for i in range(999):
        L.append(i)
    
    def index(request):
        current_page = request.GET.get('p')
    
        paginator = Paginator(L, 10)
        # per_page: 每页显示条目数量
        # count:    数据总个数
        # num_pages:总页数
        # page_range:总页数的索引范围,如: (1,10),(1,200)
        # page:     page对象
        try:
            posts = paginator.page(current_page)
            # has_next              是否有下一页
            # next_page_number      下一页页码
            # has_previous          是否有上一页
            # previous_page_number  上一页页码
            # object_list           分页之后的数据列表
            # number                当前页
            # paginator             paginator对象
        except PageNotAnInteger:
            posts = paginator.page(1)
        except EmptyPage:
            posts = paginator.page(paginator.num_pages)
        return render(request, 'index.html', {'posts': posts})
    
    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
    <ul>
        {% for item in posts %}
            <li>{{ item }}</li>
        {% endfor %}
    </ul>
    
    <div class="pagination">
          <span class="step-links">
            {% if posts.has_previous %}
                <a href="?p={{ posts.previous_page_number }}">Previous</a>
            {% endif %}
              <span class="current">
                Page {{ posts.number }} of {{ posts.paginator.num_pages }}.
              </span>
              {% if posts.has_next %}
                  <a href="?p={{ posts.next_page_number }}">Next</a>
              {% endif %}
          </span>
    
    </div>
    </body>
    </html>
    HTML部分
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  • 原文地址:https://www.cnblogs.com/yj0405/p/14748699.html
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