使用作为上下文传递的值在模板中进行计算以显示内容

Question

我在使用通过我的视图传入的上下文显示一些div时遇到了问题。在我的views.py中，我传递了一个值“total_used”和"total“。

views.py：

def home(request):
    context = {
        "reward": [
            {
                "total": 5,
                "total_used": 2
            }
        ]
    }
    return render(request, "web/index.html", context)

模板：

  {% with ''|center:reward.total_used as range %}
  {% for _ in range %}
      <div class="red"></div>
  {% endfor %}
  {% endwith %}

  <div class="blue"></div>

  <div id="reward-count">
      <h5>{{ reward.total_used }}/{{ reward.total }}</h5>
  </div>

例如，我想要2个带有红色类的div和3个带有蓝色类的div (reward.total- reward.total_used)。

我试过了，但不起作用：

  {% with ''|center:reward.total_used as range %}
  {% for _ in range %}
      <div class="red"></div>
  {% endfor %}
  {% endwith %}

    {% with ''|center:reward.total-reward.total_used as range %}
  {% for _ in range %}
      <div class="blue"></div>
  {% endfor %}
  {% endwith %}

  <div id="reward-count">
      <h5>{{ reward.total_used }}/{{ reward.total }}</h5>
  </div>

Answer 1

从context定义中删除方括号[]。您的views.py应该如下所示：

def home(request):
    context = {
        "reward": {"total": 5, "total_used": 2}        
    }
    return render(request, "web/index.html", context)

Answer 2

我最终在视图中计算total-total_used，然后将其添加到我的上下文中：

views.py：

def home(request):
    context = {
        "rewards": [
            {
                "total": 5,
                "total_used": 2
            },
            {
                "total": 7,
                "total_used": 1        
            }
        ]
    }

    for  reward in context['rewards']:
        reward['total_not_used'] = reward['total'] - reward['total_used']

    return render(request, "web/index.html", context)

模板：

{% with ''|center:reward.total_used as range %}
{% for _ in range %}
<div class="reward reward-shaded"></div>
{% endfor %}
{% endwith %}

{% with ''|center:reward.total_not_used as range %}
{% for _ in range %}
<div class="reward"></div>
{% endfor %}
{% endwith %}

<div id="reward-count">
    <h5>{{ reward.total_used }}/{{ reward.total }}</h5>
</div>