Python的转换类型的字典的平面列表以层次树

问题描述 投票:0回答:2

我一直有麻烦尝试以下列表转换:

lst = [
    {"id": 0, "job": "CEO", "ManagerID": 0, "name": "John Smith"},
    {"id": 1, "job": "Medical Manager", "ManagerID": 0, "name": "Medic 1"},
    {"id": 2, "job": "Medical Assist", "ManagerID": 1, "name": "Medic 2"},
    {"id": 3, "job": "ICT Manager", "ManagerID": 0, "name": "ICT 1"},
    {"id": 4, "job": "ICT Assist", "ManagerID": 3, "name": "ICT 2"},
    {"id": 5, "job": "ICT Junior", "ManagerID": 4, "name": "ICT 3"}
]

到像格式

output = [
    {"id": 0, "job": "CEO", "ManagerID": 0, "name": "John Smith", "children" : [
        { "id":1, "job": "Medical Manager", "name": "Medic 1", "children" : [
            {"id": 2, "job": "Medical Assist", "name": "Medic 2"}
            ]
        },
        {"id": 3, "job": "ICT Manager", "name": "ICT 1", "children":[
            {"id": 4, "job": "ICT Assist", "name": "ICT 2", "children" : [
                {"id": 5, "job": "ICT Junior", "name": "ICT 3"}
            ]}
        ]}
    ],
}]

分别有一个根节点(经理ID = 0)中的任一切分支。

我试图从another question适应代码,但我无法产生这种需要的格式

我一直在使用的代码如下,但是这还是有父节点的重复

classes = [] #everyones id
for item in lst:
    name = item['id']
    if name not in classes:
        classes.append(name)

treenodes = {}
root_node = None

for item in lst: # Create  tree nodes
    item['children'] = []
    name = item['id']
    treenodes[name] = item
    parent = item['ManagerID']
    if parent not in classes: # parent is root node, create
        if parent not in treenodes:
            node = {}
            node['ManagerID'] = 0 #set manager to root
            node['children'] = []
            node['id'] = parent
            root_node = node
            treenodes[parent] = node

# Connect parents and children
for item in lst: # Create  tree nodes
    parent = item['ManagerID']
    parent_node = treenodes[parent]
    parent_node['children'].append(item)

output = treenodes

任何帮助极大的赞赏。

python list dictionary tree hierarchy
2个回答
1
投票

您的代码实际上是工作,但你需要采取treenodes[0]条目(CEO)。中treenodes的键值对的剩余部分在那里只是记账,轻松地找到指定的经理给定雇员的条目。

如果你不能指望0作为根节点的ID,那么你可以使用该CEO被标记为自我管理的事实;根节点是一个当经理ID指向自己的ID。更常见的情况是,根节点根本就没有父ID。

您还增加了CEO自己children列表(首席执行官经理ID是自己的ID),所以你必须在你的树递归引用。

你找到的代码是不清晰的,最有效的。我会从建立到id复制的对象(所以你原来lst字典不变)一本字典,然后在该结构循环,并将条目添加到他们的经理ID条目。我使用的是“根节点自我参照”规则(因此经理ID等于自己的ID):

employees = {}
managers = set()
root_id = None
for emp in lst:
    id, mid = emp['id'], emp['ManagerID']
    # create a copy of emp, and add a "children" list
    employees[id] = {**emp, 'children': []}
    managers.add(mid)
    if id == mid:
        # the root of the tree references itself as the manager
        root_id = id

# add empty manager entries for missing manager IDs, reporting to root ID.
for id in managers - employees.keys():
    employees[id] = {
        'id': id, 'ManagerID': root_id, 'children': [],
        'job': None, 'name': None
    }

for id, emp in employees.items():
    manager = employees[emp.pop('ManagerID')]
    if id != root_id:  # don't add the root to anything
        manager['children'].append(emp)

output = employees[root_id]

上面使用了一套跟踪管理器的ID已经看到的,所以你可以平凡添加缺少的经理项(在这种情况下,向CEO汇报)。

为了您的输入,产生:

{'id': 0, 'job': 'CEO', 'name': 'John Smith', 'children':
    [{'id': 1, 'job': 'Medical Manager', 'name': 'Medic 1', 'children':
        [{'id': 2, 'job': 'Medical Assist', 'name': 'Medic 2', 'children': []}],
     },
     {'id': 3, 'job': 'ICT Manager', 'name': 'ICT 1', 'children':
        [{'id': 4, 'job': 'ICT Assist', 'name': 'ICT 2', 'children':
            [{'id': 5, 'job': 'ICT Junior', 'name': 'ICT 3', 'children': []}]
         }]
     }]
}

2
投票

下面是建立等级递归版本。

递归版本

from pprint import pprint


def to_lookup(employees):
    employee_lookup = dict()
    for employee in employees:
        if employee["id"] != employee["ManagerID"]:
            manager_id = employee["ManagerID"]
            children = employee_lookup.get(manager_id)
            if not children:
                children = employee_lookup[manager_id] = list()
            children.append(employee.copy())
        else:
            manager = employee.copy()
    return manager, employee_lookup


def build_hierarchy(manager, employee_lookup):
    employees = employee_lookup.get(manager["id"], list())
    for employee in employees:
        build_hierarchy(employee, employee_lookup)
    if employees:
        manager['children'] = employees
    return manager


employees = [
    {"id": 0, "job": "CEO", "ManagerID": 0, "name": "John Smith"},
    {"id": 1, "job": "Medical Manager", "ManagerID": 0, "name": "Medic 1"},
    {"id": 2, "job": "Medical Assist", "ManagerID": 1, "name": "Medic 2"},
    {"id": 3, "job": "ICT Manager", "ManagerID": 0, "name": "ICT 1"},
    {"id": 4, "job": "ICT Assist", "ManagerID": 3, "name": "ICT 2"},
    {"id": 5, "job": "ICT Junior", "ManagerID": 4, "name": "ICT 3"}
]

manager, employee_lookup = to_lookup(employees)
hierarchy = build_hierarchy(manager, employee_lookup)
pprint(hierarchy)

产量

{'ManagerID': 0,
 'children': [{'ManagerID': 0,
               'children': [{'ManagerID': 1,
                             'id': 2,
                             'job': 'Medical Assist',
                             'name': 'Medic 2'}],
               'id': 1,
               'job': 'Medical Manager',
               'name': 'Medic 1'},
              {'ManagerID': 0,
               'children': [{'ManagerID': 3,
                             'children': [{'ManagerID': 4,
                                           'id': 5,
                                           'job': 'ICT Junior',
                                           'name': 'ICT 3'}],
                             'id': 4,
                             'job': 'ICT Assist',
                             'name': 'ICT 2'}],
               'id': 3,
               'job': 'ICT Manager',
               'name': 'ICT 1'}],
 'id': 0,
 'job': 'CEO',
 'name': 'John Smith'}

性能测试

hierarchy_size = 2000000

employees = [
    {"id": 0, "ManagerID": 0},
]
for idx in range(1, hierarchy_size):
    manager_id = random.randint(0, idx - 1)
    employees.append({"id": idx, "ManagerID": manager_id})

start = datetime.datetime.now()

manager, employee_lookup = to_lookup(employees)
hierarchy = build_hierarchy(manager, employee_lookup)

print(datetime.datetime.now() - start)
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