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超轻量级php框架startmvc

Python Django 添加首页尾页上一页下一页代码实例

更新时间:2020-07-25 23:12:01 作者:startmvc
添加首页和尾页:views.py:fromdjango.shortcutsimportrenderfromapp01importmodelsdefbook_list(request):#从URL中

添加首页和尾页:

views.py:


from django.shortcuts import render
from app01 import models
def book_list(request):
 # 从 URL 中取参数
 page_num = request.GET.get("page")
 print(page_num, type(page_num))
 page_num = int(page_num) 
 # 定义两个变量保存数据从哪儿取到哪儿
 data_start = (page_num - 1) * 10
 data_end = page_num * 10 
 # 书籍总数
 total_count = models.Book.objects.all().count() 
 # 每一页显示多少条数据
 per_page = 10
 # 总共需要多少页码来显示
 total_page, m = divmod(total_count, per_page) 
 # 页面上最多展示的页码
 max_page = 11
 half_max_page = max_page // 2
 
 # 页面上展示的页码的开始页
 page_start = page_num - half_max_page
 # 页面上展示的页码的结束页
 page_end = page_num + half_max_page 
 # 如果当前页减一半比 1 小
 if page_start <= 1:
 page_start = 1
 page_end = max_page
 # 如果当前页加一半比总页码还大
 if page_end > total_page:
 page_end = total_page
 page_start = total_page - max_page + 1 
 # 如果还有数据
 if m:
 total_page += 1 
 all_book = models.Book.objects.all()[data_start:data_end] 
 # 拼接 html 的分页代码
 html_list = [] 
 # 添加首页按钮
 html_list.append('<li><a href="/books/?page=1" rel="external nofollow" >首页</a></li>')
 # 展示的页码
 for i in range(page_start, page_end + 1):
 tmp = '<li><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 html_list.append(tmp) 
 # 添加尾页按钮
 html_list.append('<li><a href="/books/?page={}" rel="external nofollow" >尾页</a></li>'.format(total_page)) 
 page_html = "".join(html_list) # 拼接 html 的分页代码 
 return render(request, "book_list.html", {"books": all_book, "page_html": page_html})

book_list.html:


<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>书籍列表</title>
 <link rel="stylesheet" href="/static/bootstrap/css/bootstrap.min.css" rel="external nofollow" rel="external nofollow" >
</head>
<body> 
<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 books %}
 <tr>
 <td>{{ forloop.counter }}</td>
 <td>{{ book.id }}</td>
 <td>{{ book.title }}</td>
 </tr>
 {% endfor %}
 </tbody>
 </table> 
 <nav aria-label="Page navigation">
 <ul class="pagination">
 <li>
 {{ page_html|safe }}
 </li>
 </ul>
 </nav>
</div> 
</body>
</html>

运行结果:

添加上一页、下一页:

views.py:


from django.shortcuts import render
from app01 import models 
def book_list(request):
 # 从 URL 中取参数
 page_num = request.GET.get("page")
 print(page_num, type(page_num))
 page_num = int(page_num) 
 # 定义两个变量保存数据从哪儿取到哪儿
 data_start = (page_num - 1) * 10
 data_end = page_num * 10 
 # 书籍总数
 total_count = models.Book.objects.all().count() 
 # 每一页显示多少条数据
 per_page = 10 
 # 总共需要多少页码来显示
 total_page, m = divmod(total_count, per_page) 
 # 页面上最多展示的页码
 max_page = 11
 half_max_page = max_page // 2 
 # 页面上展示的页码的开始页
 page_start = page_num - half_max_page
 # 页面上展示的页码的结束页
 page_end = page_num + half_max_page 
 # 如果当前页减一半比 1 小
 if page_start <= 1:
 page_start = 1
 page_end = max_page
 # 如果当前页加一半比总页码还大
 if page_end > total_page:
 page_end = total_page
 page_start = total_page - max_page + 1 
 # 如果还有数据
 if m:
 total_page += 1 
 all_book = models.Book.objects.all()[data_start:data_end] 
 # 拼接 html 的分页代码
 html_list = [] 
 # 添加首页按钮
 html_list.append('<li><a href="/book_list/?page=1" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a></li>') 
 # 如果是第一页,就没有上一页
 if page_num <= 1:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1))
 else:
 # 加一个上一页的标签
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1)) 
 # 展示的页码
 for i in range(page_start, page_end + 1):
 # 给当前页添加 active
 if i == page_num:
 tmp = '<li class="active"><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 else:
 tmp = '<li><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 html_list.append(tmp) 
 # 如果是最后一页,就没有下一页
 if page_num >= total_page:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>')
 else:
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>'.format(page_num+1)) 
 # 添加尾页按钮
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >尾页</a></li>'.format(total_page))
 
 page_html = "".join(html_list) # 拼接 html 的分页代码
 return render(request, "book_list.html", {"books": all_book, "page_html": page_html})

book_list.html:


<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>书籍列表</title>
 <link rel="stylesheet" href="/static/bootstrap/css/bootstrap.min.css" rel="external nofollow" rel="external nofollow" >
</head>
<body> 
<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 books %}
 <tr>
 <td>{{ forloop.counter }}</td>
 <td>{{ book.id }}</td>
 <td>{{ book.title }}</td>
 </tr>
 {% endfor %} 
 </tbody>
 </table>
 <nav aria-label="Page navigation">
 <ul class="pagination">
 <li>
 {{ page_html|safe }}
 </li>
 </ul>
 </nav> 
</div>
</body>
</html>

运行结果:

后续改进:

处理用户传给 url 的 page 参数异常的值的情况

例如:

访问,http://127.0.0.1:8888/book_list/?page=a

访问,http://127.0.0.1:8888/book_list/?page=-1

都会出错

改进:


from django.shortcuts import render
from app01 import models
def book_list(request):
 # 从 URL 中取参数
 page_num = request.GET.get("page")
 print(page_num, type(page_num)) # page_num 为 str 类型
 # 书籍总数
 total_count = models.Book.objects.all().count() 
 # 每一页显示多少条数据
 per_page = 10 
 # 总共需要多少页码来显示
 total_page, m = divmod(total_count, per_page) 
 # 如果还有数据
 if m:
 total_page += 1
 try:
 page_num = int(page_num)
 # 如果输入的页码数超过了最大的页码数,默认返回最后一页
 if page_num > total_page:
 page_num = total_page
 # 如果输入的页码数小于 1,则返回第一页
 if page_num < 1:
 page_num = 1
 except Exception as e:
 # 当输入的页码不是正经数字的时候 默认返回第一页的数据
 page_num = 1
 # 定义两个变量保存数据从哪儿取到哪儿
 data_start = (page_num - 1) * 10
 data_end = page_num * 10 
 # 页面上最多展示的页码
 max_page = 11
 half_max_page = max_page // 2
 # 页面上展示的页码的开始页
 page_start = page_num - half_max_page
 # 页面上展示的页码的结束页
 page_end = page_num + half_max_page 
 # 如果当前页减一半比 1 小
 if page_start <= 1:
 page_start = 1
 page_end = max_page
 # 如果当前页加一半比总页码还大
 if page_end > total_page:
 page_end = total_page
 page_start = total_page - max_page + 1 
 all_book = models.Book.objects.all()[data_start:data_end] 
 # 拼接 html 的分页代码
 html_list = [] 
 # 添加首页按钮
 html_list.append('<li><a href="/book_list/?page=1" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a></li>') 
 # 如果是第一页,就没有上一页
 if page_num <= 1:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1))
 else:
 # 加一个上一页的标签
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1))
 # 展示的页码
 for i in range(page_start, page_end + 1):
 # 给当前页添加 active
 if i == page_num:
 tmp = '<li class="active"><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 else:
 tmp = '<li><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 html_list.append(tmp) 
 # 如果是最后一页,就没有下一页
 if page_num >= total_page:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>')
 else:
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>'.format(page_num+1)) 
 # 添加尾页按钮
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >尾页</a></li>'.format(total_page))
 
 page_html = "".join(html_list) # 拼接 html 的分页代码
 return render(request, "book_list.html", {"books": all_book, "page_html": page_html})

如果数据库中的数据数少于 max_page,则会显示负数的页数

例如数据库中只有 21 条数据:

改进:


from django.shortcuts import render
from app01 import models
def book_list(request):
 # 从 URL 中取参数
 page_num = request.GET.get("page")
 print(page_num, type(page_num)) # page_num 为 str 类型 
 # 书籍总数
 total_count = models.Book.objects.all().count() 
 # 每一页显示多少条数据
 per_page = 10 
 # 总共需要多少页码来显示
 total_page, m = divmod(total_count, per_page) 
 # 如果还有数据
 if m:
 total_page += 1
 try:
 page_num = int(page_num)
 # 如果输入的页码数超过了最大的页码数,默认返回最后一页
 if page_num > total_page:
 page_num = total_page
 # 如果输入的页码数小于 1,则返回第一页
 if page_num < 1:
 page_num = 1
 except Exception as e:
 # 当输入的页码不是正经数字的时候 默认返回第一页的数据
 page_num = 1 
 # 定义两个变量保存数据从哪儿取到哪儿
 data_start = (page_num - 1) * 10
 data_end = page_num * 10 
 # 页面上最多展示的页码
 max_page = 11
 # 如果总页码数小于页面上最多展示的页码
 if total_page < max_page:
 max_page = total_page
 half_max_page = max_page // 2 
 # 页面上展示的页码的开始页
 page_start = page_num - half_max_page
 # 页面上展示的页码的结束页
 page_end = page_num + half_max_page 
 # 如果当前页减一半比 1 小
 if page_start <= 1:
 page_start = 1
 page_end = max_page
 # 如果当前页加一半比总页码还大
 if page_end > total_page:
 page_end = total_page
 page_start = total_page - max_page + 1 
 all_book = models.Book.objects.all()[data_start:data_end] 
 # 拼接 html 的分页代码
 html_list = [] 
 # 添加首页按钮
 html_list.append('<li><a href="/book_list/?page=1" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a></li>') 
 # 如果是第一页,就没有上一页
 if page_num <= 1:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1))
 else:
 # 加一个上一页的标签
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">«</span></a></li>'.format(page_num-1))
 # 展示的页码
 for i in range(page_start, page_end + 1):
 # 给当前页添加 active
 if i == page_num:
 tmp = '<li class="active"><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 else:
 tmp = '<li><a href="/book_list/?page={0}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >{0}</a></li>'.format(i)
 html_list.append(tmp) 
 # 如果是最后一页,就没有下一页
 if page_num >= total_page:
 html_list.append('<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>')
 else:
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ><span aria-hidden="true">»</span></a></li>'.format(page_num+1)) 
 # 添加尾页按钮
 html_list.append('<li><a href="/book_list/?page={}" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >尾页</a></li>'.format(total_page)) 
 page_html = "".join(html_list) # 拼接 html 的分页代码
 return render(request, "book_list.html", {"books": all_book, "page_html": page_html})

运行结果:

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

python django 添加 首页 尾页 上一页 下一页