python 多级处理

多数据提取

comment_list = [
    {'id': 1, 'news_id': 1, 'user_id': 10, 'content': "写的什么玩意呀", 'reply_id': None},
    {'id': 2, 'news_id': 1, 'user_id': 11, 'content': "还真不是玩意 ", 'reply_id': 1},
    {'id': 3, 'news_id': 1, 'user_id': 12, 'content': "写的真好 ", 'reply_id': 1},
    {'id': 4, 'news_id': 1, 'user_id': 11, 'content': "写的真好 ", 'reply_id': 3},
    {'id': 5, 'news_id': 1, 'user_id': 19, 'content': "sdfsfsdsd ", 'reply_id': None},
]


comment_dict = {}
for row in comment_list:
    row['child'] = []
    comment_dict[row['id']] = row

# a = [1,2,3]
# b = a
# b 等于的是a列表的内存地址 ， 所有改变b里面的值a里面也会跟着变化
# 字典也是

for row in comment_list:
    if row['reply_id']:
        reply_id = row['reply_id']
        comment_dict[reply_id]['child'].append(row)

commen_reuslt = {}

# 把根数据取出来
for k,v in comment_dict.items():
    if v['reply_id'] == None:
        commen_reuslt[k] = v

print(len(commen_reuslt), commen_reuslt)

打印结果：

2 {1: {'child': [
    {'child': [], 'reply_id': 1, 'content': '还真不是玩意 ', 'news_id': 1, 'user_id': 11, 'id': 2},
    {'child': [
        {'child': [], 'reply_id': 3, 'content': '写的真好 ', 'news_id': 1, 'user_id': 11, 'id': 4}
        ],
   'reply_id': 1, 'content': '写的真好 ', 'news_id': 1, 'user_id': 12, 'id': 3}],
   'reply_id': None, 'content': '写的什么玩意呀', 'news_id': 1, 'user_id': 10, 'id': 1}, 
5: {'child': [], 'reply_id': None, 'content': 'sdfsfsdsd ', 'news_id': 1, 'user_id': 19, 'id': 5}}

前端页面生成：

def create_child_html(child_comment):
    prve = """
        <div class="comment">
            <div class="content">
                <ul class="list-group">
       """
    for child in child_comment:
        tpl = '<li class="list-group-item">%s</li>'
        comment_str = tpl % child['content']
        prve = prve + comment_str
        if child['child']:
            # 有孙子评论，递归执行
            child = create_child_html(child['child'])
            prve = prve + child
    end = """
       </ul>
       </div>
       </div>
       """
    return prve + end


def create_html(comment_reuslt):
    prve = """
     <div class="comment">
         <div class="content">
             <ul class="list-group">
    """
    for k, v in comment_reuslt.items():
        tpl = '<li class="list-group-item">%s</li>'
        comment_str = tpl % v['content']
        prve = prve + comment_str
        if v['child']:
            # 有子评论
            child = create_child_html(v['child'])
            print(v['child'])
            prve = prve + child
    end = """
    </ul>
    </div>
    </div>
    """
    return prve + end

前端样式(左边距)：

.comment > .content {
       margin-left: 30px;
}

多级处理也适用后台的动态菜单

后台管理，在django中如果有后台，前端、后台要分别建立项目
　　- 简单菜单(适用于固定个数菜单)
　　- 动态菜单
　　　　用到根菜单和子菜单，就要用到多级处理