Posted in Python onAugust 21, 2019
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三水点靠木。
Python Django 添加首页尾页上一页下一页代码实例
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Sch01aR#声明:登载此文出于传递更多信息之目的,并不意味着赞同其观点或证实其描述。
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