递归组合字典

Question

好的，这就是我的想法。我有两个带有对象组的字典，如下所示：

groups = {
    'servers': ['unix_servers', 'windows_servers'],
    'unix_servers': ['server_a', 'server_b', 'server_group'],
    'windows_servers': ['server_c', 'server_d'],
    'server_group': ['server_e', 'server_f']
}

hosts = {
    'server_a': '10.0.0.1',
    'server_b': '10.0.0.2',
    'server_c': '10.0.0.3',
    'server_d': '10.0.0.4',
    'server_e': '10.0.0.5',
    'server_f': '10.0.0.6'
}

我正在寻找的输出是：

d3 = {
    'servers': {
        'unix_servers': {
            'server_a': '10.0.0.1',
            'server_b': '10.0.0.2',
            'server_group': {
                'server_e': '10.0.0.5',
                'server_f': '10.0.0.6'
            }
        },
        'windows_servers': {
            'server_c': '10.0.0.3',
            'server_d': '10.0.0.4'
        }
    }
}

我遇到的问题是我事先不知道有多少递归级别，因为嵌套组理论上可以无限进行。此外，我无法确定哪些键应该是组合字典中的顶级键。

我目前有以下：

def resolve(d1, d2):
for k, v in d1.items():
    for i in v:
        if i in d2.keys():
            d3[k] = {i: d2[i]}

这会返回：

{
  "servers": {
    "unix_servers": {
      "server_a": "10.0.0.1",
      "server_b": "10.0.0.2",
      "server_group": {
        "server_e": "10.0.0.5",
        "server_f": "10.0.0.6"
      }
    },
    "windows_servers": {
      "server_c": "10.0.0.3",
      "server_d": "10.0.0.4"
    }
  },
  "unix_servers": {
    "server_b": "10.0.0.2"
  },
  "windows_servers": {
    "server_d": "10.0.0.4"
  },
  "server_group": {
    "server_f": "10.0.0.6"
  }
}

这很接近，但它显然缺少递归并且不处理键的嵌套。主要是在这里找指针，递归逻辑还没点到我...

Answer 1

我认为这是你想要的：

def resolve(groups, hosts):
    # Groups that have already been resolved
    resolved_groups = {}
    # Group names that are not root
    non_root = set()
    # Make dict with resolution of each group
    result = {}
    for name in groups:
        result[name] = _resolve_rec(name, groups, hosts, resolved_groups, non_root)
    # Remove groups that are not root
    for name in groups:
        if name in non_root:
            del result[name]
    return result

def _resolve_rec(name, groups, hosts, resolved_groups, non_root):
    # If group has already been resolved finish
    if name in resolved_groups:
        return resolved_groups[name]
    # If it is a host finish
    if name in hosts:
        return hosts[name]
    # New group resolution
    resolved = {}
    for child in groups[name]:
        # Resolve each child
        resolved[child] = _resolve_rec(child, groups, hosts, resolved_groups, non_root)
        # Mark child as non-root
        non_root.add(child)
    # Save to resolved groups
    resolved_groups[name] = resolved
    return resolved

用你的例子：

groups = {
    'servers': ['unix_servers', 'windows_servers'],
    'unix_servers': ['server_a', 'server_b', 'server_group'],
    'windows_servers': ['server_c', 'server_d'],
    'server_group': ['server_e', 'server_f']
}

hosts = {
    'server_a': '10.0.0.1',
    'server_b': '10.0.0.2',
    'server_c': '10.0.0.3',
    'server_d': '10.0.0.4',
    'server_e': '10.0.0.5',
    'server_f': '10.0.0.6'
}

d3 = {
    'servers': {
        'unix_servers': {
            'server_a': '10.0.0.1',
            'server_b': '10.0.0.2',
            'server_group': {
                'server_e': '10.0.0.5',
                'server_f': '10.0.0.6'
            }
        },
        'windows_servers': {
            'server_c': '10.0.0.3',
            'server_d': '10.0.0.4'
        }
    }
}


print(resolve(groups, hosts) == d3)
# True

请注意，如果您的组 A 包含组 B 但组 B 包含组 A，则对于格式错误的输入，这可能会陷入无限递归。

Answer 2

d3={}
main={}
for i in groups['servers']:
    if(i in groups):
        d={}
        for j in groups[i]:
            if(j in groups):
                dd={}
                for k in groups[j]:
                    dd[k]=hosts[k]
                d[j]=dd
            else:
                d[j]=hosts[j]
        main[i]=d
d3['servers']=main
print(d3)

这会给：

{
    'servers': 
    {
        'unix_servers': 
        {
            'server_group': 
            {
                'server_f': '10.0.0.6', 
                'server_e': '10.0.0.5'
            }, 
            'server_b': '10.0.0.2',
            'server_a': '10.0.0.1'
        }, 
        'windows_servers': 
        {
            'server_c': '10.0.0.3', 
            'server_d': '10.0.0.4'
        }
    }
}

Answer 3

我猜它只需要两个循环，不再需要了。在这里，dict 组将被更新，更准确地说，它会丢失一些键值。

groups = {k: {s: None for s in subs} for k, subs in groups.items()}                                                                                                                                                        

for k, subs in groups.items():                                                                                                                                                                                        
    for subs_k, subs_v in subs.items():                                                                                                                                                                                       
        if subs_v is not None:                                                                                                                                                                                         
            continue                                                                                                                                                                                               
        if subs_k in groups:                                                                                                                                                                                           
            groups[k][subs_k] = groups[subs_k]                                                                                                                                                                             
            del groups[subs_k]                                                                                                                                                                                       
        else:                                                                                                                                                                                                      
            groups[k][subs_k] = hosts[subs_k]


print(groups)

你可能想用defaultdict重写它

Answer 4

假设您对可能具有交叉引用数据结构感到满意，那么您不一定需要在此处使用递归。

from itertools import chain

group_dicts = {k: {} for k in groups}

for g in group_dicts:
    for child_key in groups[g]:
        child = group_dicts.get(child_key, hosts.get(child_key))
        group_dicts[g][child_key] = child

# remove entries that are referenced at least once
not_top_levels = set(chain.from_iterable(groups.values()))
result = {g: group_dicts[g] for g in group_dicts if g not in not_top_levels}

与其他解决方案不同，这将正确处理循环和无限递归组，因为所有 dict 引用都是共享的。当您的groups 在拓扑上描述一棵树时，这将与递归解决方案完全相同。但是，如果您的groups 在拓扑上描述了一个有向无环图，则此解决方案将共享所有出现多次的节点的字典，而递归解决方案会将重复项复制并扩展为常规树，这不会如果您不需要改变字典，这确实是一个问题。如果您的groups 在拓扑上描述了一个带有循环的图，那么这将创建这些循环，而递归解决方案将由于无限递归而下降。

Answer 5

你可以使用简单的递归：

def build(val): 
  return {i:build(i) for i in groups[val]} if val in groups else hosts[val]

---

import json
print(json.dumps({'servers':build('servers')}, indent=4))

输出：

{
  "servers": {
    "unix_servers": {
        "server_a": "10.0.0.1",
        "server_b": "10.0.0.2",
        "server_group": {
            "server_e": "10.0.0.5",
            "server_f": "10.0.0.6"
        }
    },
    "windows_servers": {
        "server_c": "10.0.0.3",
        "server_d": "10.0.0.4"
     }
  }
}

Answer 6

python新手我一直在苦苦挣扎，但终于找到了解决方案，虽然它很长。

groups = {
    'servers': ['unix_servers', 'windows_servers'],
    'unix_servers': ['server_a', 'server_b', 'server_group'],
    'windows_servers': ['server_c', 'server_d'],
    'server_group': ['server_e', 'server_f']
}

hosts = {
    'server_a': '10.0.0.1',
    'server_b': '10.0.0.2',
    'server_c': '10.0.0.3',
    'server_d': '10.0.0.4',
    'server_e': '10.0.0.5',
    'server_f': '10.0.0.6'
}

result = {}

parent = '';

levels = [];

def check(s,r):
    if(r[s]==''): #check for each blank element in the result recursively
        sublist = {}
        for k in groups[s]: # check if the key exist in group if exist append children to result.   
            if k in hosts :
                sublist[k] = hosts[k] # check if host exist in hosts for this key
            else:
                sublist[k]=''
        if(key_exist(result, s)): # check if the key exist in result if exist append to result.             
            d = result 
            p = None
            for key in levels:
                p = d
                d = d[key]
            p[key] = sublist
            del levels[:]
        for x in sublist :
            if(sublist[x] == ''):
                check(x,p[key])

def resolve(r):
    for s in r:
        if(isinstance(r[s],dict)):
            return resolve(r[s])
        else:
            check(s,r)


def key_exist(groups, key): 
    for s in groups:
        if key in groups:
            levels.append(key);
            return True
        else:
            if(isinstance(groups[s],dict)):
                levels.append(s);
                return key_exist(groups[s], key)
    return False

# Find the root or parent element
for k in groups.keys(): 
    found = False
    for j in groups.keys(): 
        if k in groups[j]:
            found = False
        else:
            found = True
    if(found):
        parent = k  # root or parent element

# start making result with root element 
s = {}
for k in groups[parent]:
    s[k]='' # initialize child elements with blank
result[parent] = s 

resolve(result) 

print(result)