自定义分页

Django提供了一些类来管理分页的数据,类位于django/core/paginator.py中

from django.core.paginator import Paginator
objects=[]
for i in range(20):
    objects.append("图书%s"%i)
p=Paginator(objects,4)  #每页的个数
print(p.count)  #数据总数
print(p.num_pages) #总页数
print(p.page_range) #页码列表
print(p.page(1)) #第一页的对象
print(p.page(1).object_list) #['图书0', '图书1', '图书2', '图书3']
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

1.在py中批量往数据库中加数据

##批量添加数据##
objs=[models.Book(title="图书{}".format(i+15)) for i in range(100)]
# 在数据库中批量创建, 10次一提交
models.Book.objects.bulk_create(objs,10)
###将数据全部删除
# models.Book.obje

2.设置分页

HTML

<div class="container">
    <table class="table table-bordered">
      <thead>
        <tr>
            <th>序号</th>
            <th>id</th>
            <th>书名</th>
        </tr>
      </thead>
        <tbody>
        {% for book in book_list %}
            <tr>
            <td>{{ forloop.counter }}</td>
            <td>{{ book.id }}</td>
            <td>{{ book.title }}</td>
            </tr>
        {% endfor %}

        </tbody>
</table>
{#分页条#}
<nav aria-label="Page navigation">
  <ul class="pagination">

        {# 没有safe显示会有误     #}
        {{ page_html|safe }}
  </ul>
</nav>
</div>

在views设置分页

 1.在页面上将所有数据均显示出来
    book_obj=models.Book.objects.all()
    2.每页显示5条数据
    book_obj = models.Book.objects.all()[0:5]
    3.在地址栏输入要显示的页面，显示出其数据 ?page=2
    num=request.GET.get("page")  #num是字符串
    print(num,type(num))
    num=int(num)
    start=(num-1)*5
    end=num*5
    book_obj = models.Book.objects.all()[start:end]
    return render(request

加上分页条来设置

total_count = models.Book.objects.all().count()  # 统计数据的数量
    print("数量为{}".format(total_count))
    per_page = 5  # 每页显示的数量
    total_page, m = divmod(total_count, per_page)  # 如果有余数，就要在得到的整数基础上再加1页
    if m:
        total_page += 1  # 得到数字，不能直接给HTML
    ##自己拼接HTML代码
    html_str_list = []
    for i in range(1, total_page + 1):
        tmp = '<li><a href="/book_list/?page={0}">{0}</a></li>'.format(i)
        html_str_list.append(tmp)
    page_html = "".join(html_str_list)  # 标签之间没有逗号
    num = request.GET.get("page")  # num是字符串
    if num:
        num = int(num)
    else:num=1  #如果只在路径上输入/book_list/,不指定页数，就默认显示第一页
    start = (num - 1) * 5
    end = num * 5
    book_obj = models.Book.objects.all()[start:end]
    return render(request,"book_list.html",{"book_list":book_obj,"page_html":page_html})

设置固定的页码数

 total_count = models.Book.objects.all().count()  # 统计数据的数量
    print("数量为{}".format(total_count))
    per_page = 5  # 每页显示的数量
    total_page, m = divmod(total_count, per_page)  # 如果有余数，就要在得到的整数基础上再加1页
    if m:
        total_page += 1  # 得到数字，不能直接给HTML
    num = request.GET.get("page")  # num是字符串
    if num:
        try:
            num = int(num)
            if num>total_page:
                num=total_page
        ##输入不是数字时，就返回第一页
        except Exception  as e:
            num=1
    else:
        num = 1  # 如果只在路径上输入/book_list/,不指定页数，就默认显示第一页
    start = (num - 1) * 5
    end = num * 5
    book_obj = models.Book.objects.all()[start:end]

    ##设置固定的页码数##
    max_page=11
    if total_page<max_page:  #如果页数小于11页
        max_page=total_page
    half_page=max_page//2 #当前页前后的页数
    #页面的开始页码
    start_page=num-half_page
    end_page=num+half_page
    if  start_page<=1:
        start_page=1
        end_page=max_page
    if end_page>total_page:
        start_page=total_page-max_page+1  #如果不加1，会显示12个
        end_page=total_page
    html_str_list = []
    for i in range(start_page, end_page+1):
        tmp = '<li><a href="/book_list/?page={0}">{0}</a></li>'.format(i)
        html_str_list.append(tmp)
    page_html = "".join(html_str_list)
    return render(request, "book_list.h

添加首页和尾页，上一页和下一页

html_str_list = []
    ##添加首页
    html_str_list.append('<li><a href="/book_list/?page=1">首页</a></li>')
    ##添加上一页
    if num<=1:  #如果是页数小于等于1，就没有上一页,就不让选了
        html_str_list.append('<li class="disabled"><a href="#" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>')
    else:
        html_str_list.append('<li><a href="/book_list/?page={}" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>'.format(num-1))
    for i in range(start_page, end_page+1):
        ##如果是当前页，就加个样式类
        if i == num:
            tmp = '<li class="active"><a href="/book_list/?page={0}">{0}</a></li>'.format(i)
        else:
            tmp = '<li><a href="/book_list/?page={0}">{0}</a></li>'.format(i)
        html_str_list.append(tmp)
    ##添加下一页
    if num >=total_page:
        html_str_list.append('<li class="disabled"><a href="#" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>')
    else:
        html_str_list.append('<li ><a href="/book_list/?page={}" aria-label="Next"><span aria-hidden="true">&raquo;</span></a></li>'.format(num+1))
    ##添加尾页
    html_str_list.append('<li><a href="/book_list/?page={}">尾页</a></li>'.format(total_page))
    page_html = "".join(html_str_list)
    return render(request, "book_list.html", {"book_list": book_obj, "page_html": page_html})

CBV版分页

page.py

"""
分页组件使用示例：

    obj = Pagination(request.GET.get('page',1),len(USER_LIST),request.path_info)
    page_user_list = USER_LIST[obj.start:obj.end]
    page_html = obj.page_html()

    return render(request,'index.html',{'users':page_user_list,'page_html':page_html})

"""
class Pagination(object):
    def __init__(self,current_page,all_count,base_url,params,per_page_num=20,pager_count=11):
        """
        封装分页相关数据
        :param current_page: 当前页
        :param all_count:    数据库中的数据总条数
        :param per_page_num: 每页显示的数据条数
        :param base_url: 分页中显示的URL前缀
        :param pager_count:  最多显示的页码个数
        """
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1

        if current_page <1:
            current_page = 1

        self.current_page = current_page

        self.all_count = all_count
        self.per_page_num = per_page_num

        self.base_url = base_url
        # 总页码
        all_pager, tmp = divmod(all_count, per_page_num)
        if tmp:
            all_pager += 1
        self.all_pager = all_pager


        self.pager_count = pager_count
        self.pager_count_half = int((pager_count - 1) / 2)


        # GET请求数据
        import copy
        self.params=copy.deepcopy(params)  # request.GET   {"nid":1}
    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_num
    @property
    def end(self):
        return self.current_page * self.per_page_num
    def page_html(self):
        # 如果总页码 < 11个：
        if self.all_pager <= self.pager_count:
            pager_start = 1
            pager_end = self.all_pager + 1
        # 总页码  > 11
        else:
            # 当前页如果<=5
            if self.current_page <= self.pager_count_half:
                pager_start = 1
                pager_end = self.pager_count + 1
            # 当前页大于5
            else:
                # 页码翻到最后
                if (self.current_page + self.pager_count_half) > self.all_pager:
                    pager_start = self.all_pager - self.pager_count + 1
                    pager_end = self.all_pager + 1
                else:
                    pager_start = self.current_page - self.pager_count_half
                    pager_end = self.current_page + self.pager_count_half + 1
        page_html_list = []
        page_html_list.append('<nav aria-label="Page navigation"><ul class="pagination">')
        first_page = '<li><a href="/%s?page=%s">首页</a></li>' % (self.base_url,1,)
        page_html_list.append(first_page)
        if self.current_page <= 1:
            prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
        else:
            prev_page = '<li><a href="/%s?page=%s">上一页</a></li>' % (self.base_url,self.current_page - 1,)
        page_html_list.append(prev_page)
        for i in range(pager_start, pager_end):
            self.params["page"]=i
            if i == self.current_page:
                temp = '<li class="active"><a href="/%s?%s">%s</a></li>' % (self.base_url,self.params.urlencode(), i,)
            else:
                temp = '<li><a href="/%s?%s">%s</a></li>' % (self.base_url,self.params.urlencode(), i,)
            page_html_list.append(temp)

        if self.current_page >= self.all_pager:
            next_page = '<li class="disabled"><a href="#">下一页</a></li>'
        else:
            next_page = '<li><a href="/%s?page=%s">下一页</a></li>' % (self.base_url,self.current_page + 1,)
        page_html_list.append(next_page)

        last_page = '<li><a href="/%s?page=%s">尾页</a></li>' % (self.base_url,self.all_pager,)
        page_html_list.append(last_page)
        page_html_list.append('</ul></nav>')
        return ''.join(page_html_list)

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <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>

<ul>
    {% for book in book_list %}
    <li>{{ book.title }}----{{ book.price }}</li>
    {% endfor %}

</ul>


{{ pagination.page_html|safe }}



</body>
</html>

from app01 import models

def index(request):
      book_list=models.BooK.objects.all()
    from app01.page import Pagination
    current_page=request.GET.get("page")

    pagination=Pagination(current_page,book_list.count(),"index",request.GET,per_page_num=5)

    book_list=book_list[pagination.start:pagination.end]

    return render(request,"index.html",locals())

import pymysql
conn =pymysql.connect(host="10.110.1.90",
                      port=3306,
                      user="php",
                      password="MySQL57.huayingjuhe.com",
                      database="fdm",
                      charset="utf8mb4"
                      )

cursor =conn.cursor(cursor=pymysql.cursors.DictCursor)

def pageinfo(page=1, pagesize=20, total=0 ):
    """只显示五页的页码"""
    page = int(page)
    if page <= 0 :
        page = 1

    pagesize = int(pagesize)
    if pagesize <= 0 :
        pagesize = 20

    total = int(total)
    totalpage = abs(((-1) * total)// pagesize )
    if page > totalpage and totalpage > 0:
        page = totalpage

    offset = (page - 1) * pagesize

    d = {"page" : page, "pagesize" : pagesize, "offset" : offset, "total" : total }

    d["first"] = 1
    d["prev"] = page - 1 if(page > 1) else 1
    d["next"] = page + 1 if(page < totalpage) else totalpage
    d["last"] = totalpage

    l = []
    i = -4
    while i < 5 :
        if page + i  >= 1 and page +i <= totalpage :
            l.append(page + i )
        i = i + 1
    d["links"] = l

    return d


def get_movie_projects(name=None, page=1,pagesize=20):
    """分页显示"""

    where = [" id > %s "]
    args = [0]

    if name != None :
        where.append(" and ( pid = %s  or name like %s ) ")
        args.append(name)
        args.append('%'+name+'%')

    sql = "select count(*) as row_num from fdm_project where %s " % (''.join(where))
    row = cursor.execute(sql,tuple(args,))
    r = cursor.fetchall()
    total = r[0]["row_num"]
    page_info = pageinfo(page,pagesize,total)
    sql = "select *  from fdm_project where %s order by id desc limit %s offset %s " % (''.join(where),page_info["pagesize"],page_info["offset"] )
    row = cursor.execute(sql,tuple(args))
    project = cursor.fetchall()

    return {"pageinfo":page_info,"project":project}

print(get_movie_projects())