django url 多参数传递
传递多个参数的一般URL的情况是/instance-id/action/
url(r'^server/(?P<instance_id>[0-9A-Fa-f-]+)/(?P<action>.*)',
views.instance_action, name='instance_action'),
<a onclick="{% url 'instance_action' instance_id=val.id action='create_snapshot' %}"></a>