类目属性度量衡

 为了规范标准单位参数，如重量、容积、长度等属性，淘宝启动了度量衡项目。

后续taobao.itemcats.get 和 taobao.itemprops.get  会增加字段，来获取度量衡信息。

1、 类目接口：taobao.itemcats.get，增加一个字段：

1.1  taosir_cat：是否度量衡类目， true：是；false：否。

案例：

{
    "itemcats_get_response": {
        "item_cats": {
            "item_cat": [
                {
                    "cid": 134852557,
                    "is_parent": false,
                    "name": "度量衡测试类目1",
                    "parent_cid": 134846593,
                    "taosir_cat": false
                },
                {
                    "cid": 134846594,
                    "is_parent": false,
                    "name": "度量衡测试子类目2",
                    "parent_cid": 134846593,
                    "taosir_cat": true
                }
            ]
        }
    }
}

2、 类目属性接口：taobao.itemprops.get，增加两个字段。

2.1  is_taosir：是否度量衡属性，true 是；false 否。

2.2  taosir_do：度量衡信息；

2.2.1      precision：数值小数点精度。

2.2.2      type：时间类型：0表示非时间，1表示时间点，2表示时间范围。

2.2.3      std_unit_list：单位列表，attr_key为单位ID，attr_value为单位名称。

2.2.4      expr_el_list：表达式元素列表，若不是表达式度量衡，则没有该字段；

2.2.4.1   type：元素类型

2.2.4.2   text：显示文本

2.2.4.3   isShowLabel：是否只用于显示的label元素

2.2.4.4   isLabel：即用于显示又用于组装value_data的label元素

2.2.4.5   isInput：是否普通输入框

2.2.4.6   案例说明：表达式为，卖家分别输入4、5、6之后，需组装成 4X5X6，再加上卖家选择的单位（比如：cm），组装成4X5X6cm进行商品发布。那么“长”这个元素的类型就是isShowLabel；输入框的类型就是isInput；“X”的类型就是isLabel。

案例：

{
    "itemprops_get_response": {
        "item_props": {
            "item_prop": [
                {
                    "is_taosir": true,
                    "is_enum_prop": false,
                    "must": false,
                    "name": "净含量",
                    "pid": 145998403,
                    "taosir_do": {
                        "precision": 2,
                        "std_unit_list": {
                            "std_unit": [
                                {
                                    "attr_key": "34",
                                    "attr_value": "g"
                                },
                                {
                                    "attr_key": "35",
                                    "attr_value": "mg"
                                }
                            ]
                        },
                        "type": 0
                    }
                },
                {
                    "is_taosir": true,
                    "is_enum_prop": false,
                    "must": false,
                    "name": "尺寸",
                    "pid": 145994486,
                    "taosir_do": {
                        "expr_el_list": {
                           "expr_el": [
                                {
                                    "is_input": false,
                                    "is_label": false,
                                    "is_show_label": true,
                                    "text": "长",
                                    "type": 0
                                },
                                {
                                    "is_input": true,
                                    "is_label": false,
                                    "is_show_label": false,
                                    "type": 2
                                },
                                {
                                    "is_input": false,
                                    "is_label": true,
                                    "is_show_label": false,
                                    "text": "X",
                                    "type": 1
                                },
                                {
                                    "is_input": false,
                                    "is_label": false,
                                    "is_show_label": true,
                                    "text": "高",
                                    "type": 0
                                },
                                {
                                    "is_input": true,
                                    "is_label": false,
                       &a