函数在Python中没有被调用，为什么？我该怎么解决呢？

我目前正在python/django站点上工作，目前我有一个如下所示的模板

 {% extends "shopbase.html" %}
{% block pageid %}products{% endblock %}
{% block right-content %}

<img src="{{MEDIA_URL}}/local/images/assets/products.png" alt="Neal and Wolf News" class="position"/>
    <div class="products">
    <form method="post" action="{% url category category.slug %}">
    {% for product in category.products.all %}
        <div class="{% cycle 'clear' '' '' %}">
            <img src="{{MEDIA_URL}}{{download.mini.thumbnail}}" alt="{{product.name}}" class="thumbnail"/>
            <h3><a href="{% url shop.views.product category.slug product.slug %}">{{ product.product_type_name }}</a></h3>
            <p class="strap">{{ product.product_sub_name }}</p>
            <p>{{ product.strap }}</p>
            <ul class="clear">
                <li class="price"><b>&pound;{{product.price}}</b></li>
                <li class="quantity">
                    <select name="quantity_{{product.id}}">
                        <option label="1" value="1">1</option>
                        <option label="2" value="2">2</option>
                        <option label="3" value="3">3</option>
                        <option label="4" value="4">4</option>
                        <option label="5" value="5">5</option>
                        <option label="6" value="6">6</option>
                        <option label="7" value="7">7</option>
                        <option label="8" value="8">8</option>
                        <option label="9" value="9">9</option>
                    </select>
                </li>
                <li><b><a href="details">Details &gt;</a></b></li>
                <li><input type="submit" name="add_to_basket_{{product.id}}" value="Add to Basket &gt;"/></a></li>
            </ul>
        </div>
    {% endfor %}
    </form>
    </div>
{% endblock %}

def get_thumbnail(self, dimension, on=RES_X, use=USE_BOTH):
    """
    Generate a thumbnail image for this Store Object. The thumbnail will be
    of size 'dimension' on the axis specified by the on parameter (which is
    deduced from calling x_or_y). If the use parameter is set to USE_BOTH
    then the thumbnail will take priority in the generation order. In other
    words, the function checks for the existance of an uploaded thumbnail.
    If one exists, it will use that, otherwise the image field is used
    instead. Specifying either USE_IMAGE or USE_THUMBNAIL here will force
    the generation to a particular asset.
    The image is saved out as a jpeg with the quality set to 90. The
    path relative to the MEDIA_ROOT is then returned.
    """
    from PIL import Image
    import os

    if self.thumbnail and use != StoreObject.USE_IMAGE:
      source_path = str(self.thumbnail)
    elif self.image and use != StoreObject.USE_THUMBNAIL:
      source_path = str(self.image)
    else:
      return ""

    try:
      against = StoreObject.x_or_y(on)
    except KeyError:
      return ""

    target_path = os.path.join(StoreObject.GENERATED_THUMB_LOCATION, "%s-%d%s.png" % (self.slug, dimension, against))

    savepath = os.path.join(settings.MEDIA_ROOT, target_path)
    loadpath = os.path.join(settings.MEDIA_ROOT, source_path)

    if os.path.exists(savepath) and os.path.getmtime(savepath) > os.path.getmtime(loadpath):
      return target_path

    try:
      img = Image.open(loadpath)
    except IOError:
      return ""

    aspect = float(img.size[0]) / float(img.size[1])
    if against == StoreObject.RES_X:
      height = dimension / aspect
      width = dimension
    elif against == StoreObject.RES_Y:
      width = dimension * aspect
      height = dimension

    img = img.resize((width,height), Image.ANTIALIAS)

    img.convert('RGBA').save(savepath, "PNG")
    return target_path

def mini_thumbnail(self):
    """
    Generate and return the path to, a thumbnail that is 50px high
    """
    return self.get_thumbnail(50, "x")

def preview_image(self):
    """
    Generate and return the path to, a thumbnail that is 300px wide, build
    from the image field
    """
    return self.get_thumbnail(300, use=StoreObject.USE_IMAGE)

def preview_thumbnail(self):
    """
    Generate and return the path to, a thumbnail that is 300px wide, build
    from the thumbnail field
    """
    return self.get_thumbnail(300, use=StoreObject.USE_THUMBNAIL)

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现在，正如您所看到的，我正试图从数据库中提取某个项目的一些信息，并在缩略图中显示该项目的图像，该缩略图是使用product.mini_thumbnail在模板I中的缩略图功能生成的，但似乎有已知图像？但是，如果使用媒体URL打印product.image，则会得到完整大小的图像。有人能提出可能发生的事情吗？

你的模板有{{download.mini.thumbnail}}而不是{{download.mini_thumbnail}

就像Django中的很多东西一样。。。有人已经解决了这个问题，并提出了一个干净、灵活的解决方案，用于生成/存储不同大小的缩略图等。我强烈建议查看sorl缩略图项目

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更改为正确，可能应该在发布之前检查我的代码，现在仍然更改！我现在看不出有什么问题。顺便说一句，参考下载应该是产品，我的坏！缩略图实际上是在MEDIA_ROOT中创建的吗？模板生成的img src URL是什么？