Django中如何统计指定状态（Installed）的墨盒类型数量？

架构老林

2026-7-26

问题

现有一段代码用于统计每种类型的元素数量，具体代码如下：

Views.py

from django.db.models import Count

class HomeView(ListView):
    model = TypeCartridge
    template_name = 'home.html'
    
    def get_context_data(self, *args, **kwargs):
        context = super().get_context_data(*args, **kwargs)
        type_counts = TypeCartridge.objects.values('type').annotate(total=Count('type'))
        context['type_counts'] = type_counts
        return context

home.html

<div>
  {% for cartridge in object_list %}
        <div>
            <p>Number {{ cartridge.num}}: {{ cartridge.type }}, status {{ cartridge.status }}</p>
        </div>
  {% endfor %}

  <h2>Type Counts</h2>
  <ul>
    {% for type_count in type_counts %}
      <li>{{ type_count.type }} - {{ type_count.total }}</li>
    {% endfor %}
  </ul>
</div>

示例数据

num type Status
0000001 Samsung Installed
0000002 Samsung NotInstalled
0000003 Xerox Installed
0000004 Brother NotInstalled
0000005 Brother NotInstalled
0000006 Brother NotInstalled
0000007 HP Installed
0000008 HP Installed

当前运行结果

Samsung - 2
Xerox - 1
Brother - 3
HP - 2

现在需要仅统计状态为**"Installed"**的元素，期望结果如下：

Samsung - 1
Xerox - 1
HP - 2

请问如何改进这段代码？

解决方案

只需要在统计前添加过滤条件，筛选出状态为Installed的记录即可，修改Views.py中的type_counts查询语句：

修改后的Views.py代码

from django.db.models import Count

class HomeView(ListView):
    model = TypeCartridge
    template_name = 'home.html'
    
    def get_context_data(self, *args, **kwargs):
        context = super().get_context_data(*args, **kwargs)
        # 添加filter筛选状态为Installed的记录
        type_counts = TypeCartridge.objects.filter(status='Installed').values('type').annotate(total=Count('type'))
        context['type_counts'] = type_counts
        return context