Python

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">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}">{0}</a></li>'.format(i)
        html_list.append(tmp)

    # 添加尾页按钮
    html_list.append('<li><a href="/books/?page={}">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">
</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 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">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="#"><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={}"><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}">{0}</a></li>'.format(i)
        else:
            tmp = '<li><a href="/book_list/?page={0}">{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="#"><span aria-hidden="true">»</span></a></li>')
    else:
        html_list.append('<li><a href="/book_list/?page={}"><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={}">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">
</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">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="#"><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={}"><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}">{0}</a></li>'.format(i)
        else:
            tmp = '<li><a href="/book_list/?page={0}">{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="#"><span aria-hidden="true">»</span></a></li>')
    else:
        html_list.append('<li><a href="/book_list/?page={}"><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={}">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">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="#"><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={}"><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}">{0}</a></li>'.format(i)
        else:
            tmp = '<li><a href="/book_list/?page={0}">{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="#"><span aria-hidden="true">»</span></a></li>')
    else:
        html_list.append('<li><a href="/book_list/?page={}"><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={}">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：

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原文地址：https://www.cnblogs.com/sch01ar/p/11332864.html