我有三个下拉选择框,出于网络可见性的原因,我必须使用 size='' 选项扩展它们。如果我从每个框中选择一个选项,我不会收到错误,但如果我留下一个或多个框没有选择,我会收到错误:
<select id="pathology_id" name="pathology_id" size="5">
{% for pathology in pathology_list %}
<option value="{{ pathology.id }}">{{ pathology.pathology }}</option>
{% endfor %}
</select>
<select id="commodity_id" name="commodity_id" size="5">
{% for commodity in commodity_list %}
<option value="{{ commodity.id }}">{{ commodity.commodity }}</option>
{% endfor %}
</select>
<select id="technology_id" name="technology_id" size="5">
{% for technology in technology_list %}
<option value="{{ technology.id }}">{{ technology.technology }}</option>
{% endfor %}
</select>
ERROR:
MultiValueDictKeyError
Exception Value:
"Key 'pathology_id' not found in <QueryDict: {u'q': [u''],
如何对视图进行编码以接受没有选择的下拉框?