request.POST.getlist() 获取不到checkbox的值，请大神帮忙，两天了实在找不到原因

前段： <table align="center" border="3"> <tr>

                    <th>序号</th>
                    <th>设备名</th>
                    <th>型号</th>
                    <th>厂家</th>
                    <th>序列号</th>
                    <th>存放地址</th>
                    <th>进厂日期</th>
                    <th>保固日期</th>
                </tr>

                {% for i in equipment %}

                    <tr>
                    <td >

                        <input type="checkbox" name="checkbox_list" value='{{i.3}}'>{{i.3}}
                    </td>

                    <td>{{i.0}}</td>
                    <td>{{i.1}}</td>
                    <td>{{i.2}}</td>
                    <td>{{i.3}}</td>
                    <td>{{i.4}}</td>
                    <td>{{i.5}}</td>
                    <td>{{i.6}}</td>

                    </tr>
                {% endfor %}

            </table>
        </form>
            <form action="/delete_data" method="post">
                {% csrf_token %}
                <table align="center">
                <tr>
                    <td>
                        <input type="submit"  value="删除" >
                    </td>
                    </table>

后端： def delete_data(request):

check_book_list=request.POST.getlist('checkbox_list')
print(check_book_list)
if check_book_list:
    for i in check_book_list:
        equipment.objects.filter(equipment_serial_number=check_book_list).delete()
return redirect('/index')