django模版中的比较运算的方式一直是被众人所诟病的，提供的很少的几个运算符如ifequal、ifnotequal等，看起来很怪异，也不够灵活。而>,<,==等这些常见的运算完全不支持，被广大django粉丝所抱怨，每次在模板中用到比较运算时都有拍案而起的冲动-_ -!
好在django从善如流！
昨晚在阅读django的文档时，发现在最新版本的模版api中已经加入了操作符的支持，激动啊。但目前还没有放出，仍在开发版本中（New in Django Development version）。最新版本的模版加入了==, !=, <, >, <=, >=,in这几种比较运算，使用起来很方便。特别赞的是in运算，支持如下几种方式：
{% if "bc" in "abcdef" %}
This appears since "bc" is a substring of "abcdef"
{% endif %}
{% if "hello" in greetings %}
If greetings is a list or set, one element of which is the string
"hello", this will appear.
{% endif %}
{% if user in users %}
If users is a QuerySet, this will appear if user is an
instance that belongs to the QuerySet.
{% endif %}
This appears since "bc" is a substring of "abcdef"
{% endif %}
{% if "hello" in greetings %}
If greetings is a list or set, one element of which is the string
"hello", this will appear.
{% endif %}
{% if user in users %}
If users is a QuerySet, this will appear if user is an
instance that belongs to the QuerySet.
{% endif %}
很帅吧！另外操作符还支持filters，将filters的结果进行比较运算：
{% if messages|length >= 100 %}
You have lots of messages today!
{% endif %}
You have lots of messages today!
{% endif %}
更多详细说明，请猛击这里围观。
其实django的模版从1.0以来已经做出了很多改变，加入了很多方便开发的新特性，只是我没有关注过而已。以后要多加关注，养成阅读在线文档的好习惯。
希望django越来越强大，走的更远！
