Python Django 添加首页尾页上一页下一页代码实例

2019-11-25 11:54:34

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来源：转载

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添加首页和尾页：

views.py：

from django.shortcuts import renderfrom app01 import modelsdef 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：

views.py：

from django.shortcuts import renderfrom 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 renderfrom app01 import modelsdef 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 renderfrom app01 import modelsdef 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：