商品分类的无限级分类

方法一：

因为前端，需要通过循环多少成来，展示多个等级
for item in data:
    print(item.name)
    for item1 in item.children 
        item1.name
        
归档：我要把我的子集，都放在我的children列表里面

data=[
    {"cat_id":1,"name":"北京","parent_id":0},
    {"cat_id":2,"name":"上海","parent_id":0},
    {"cat_id":3,"name":"沙河","parent_id":1},
    {"cat_id":4,"name":"sb镇","parent_id":3},
    {"cat_id":5,"name":"昌平","parent_id":1},
    {"cat_id":6,"name":"青浦","parent_id":2},
]
def get_tree(data):
    lists=[]
    tree={}
    for i in data:
        tree[i['cat_id']]=i
    for item in data:
        if not item['parent_id']:
            lists.append(tree[item['cat_id']])
        else:
            if "children" not in tree[item['parent_id']]:
                tree[item['parent_id']]['children']=[]
            tree[item['parent_id']]['children'].append(tree[item['cat_id']])
    return lists

方法二：

我们数据不是有序的，但是我们要排序，并归类，把父集放在子集的前面，辈分等级通过level标明

res=[]
def get_son(data,level=0,parent_id=0,is_clear=True):
    if is_clear:
        res.clear()
    for item in data:
        if item['parent_id']==parent_id:
            item['level']=level
            res.append(item)
            get_son(data,level=level+1,parent_id=item['cat_id'],is_clear=False)
    return res