python - 从 Python 中的字典列表创建 JSON

Question

我有一个 friend 的项目数据:

arr = [{'Key':'Key 1', 'SecondKey':'SecondKey 1', 'ThirdKey':'Thirdkey 1', 'Value':100},
   {'Key':'Key 1', 'SecondKey':'SecondKey 1', 'ThirdKey':'ThirdKey 2', 'Value':130},
   {'Key':'Key 1', 'SecondKey':'SecondKey 2', 'ThirdKey':'ThirdKey 1', 'Value':230},
   {'Key':'Key 1', 'SecondKey':'SecondKey 2', 'ThirdKey':'ThirdKey 2', 'Value':300},
   {'Key':'Key 2', 'SecondKey':'SecondKey 4', 'ThirdKey':'ThirdKey 1', 'Value':111},
   {'Key':'Key 2', 'SecondKey':'SecondKey 2', 'ThirdKey':'ThirdKey 2', 'Value':400},
   {'Key':'Key 2', 'SecondKey':'SecondKey 1', 'ThirdKey':'ThirdKey 2', 'Value':230}
   ] 

我试过这样的功能:

def array_to_dict(arr, classification):
    dct = tree()
    for d in arr:
        dct[d["Key"]]=(d)
    pprint.pprint(dct)

def tree():
    return defaultdict(tree)

def array_to_dict_recursive(arr, classification):
    result = defaultdict(arr)
    for v, k in arr:
        result[k].append(v)
    final_result = [{'type': k, 'items': v} for k, v in result.items()]
    print (str(final_result))

def array_cool(arr):
    #pprint.pprint(arr)
    arr.sort(key=operator.itemgetter('Key'))
    pprint.pprint(arr)
    list1= []
    print("")
    for key, items in itertools.groupby(arr, operator.itemgetter('Key')):
        list1.append(list(items))
    pprint.pprint(list1)

我希望它以这种方式显示为 JSON 文件:

{
"Key 1": {
    "SecondKey 2": {
        "ThirdKey 2": [
            {
                "Key": "Key 1",
                "Value": 300,
                "SecondKey": "SecondKey 2",
                "ThirdKey": "ThirdKey 2"
            }
        ],
        "ThirdKey 1": [
            {
                "Key": "Key 1",
                "Value": 230,
                "SecondKey": "SecondKey 2",
                "ThirdKey": "ThirdKey 1"
            }
        ]
    },
    "SecondKey 1": {
        "ThirdKey 2": [
            {
                "Key": "Key 1",
                "Value": 130,
                "SecondKey": "SecondKey 1",
                "ThirdKey": "ThirdKey 2"
            }
        ],
        "ThirdKey 1": [
            {
                "Key": "Key 1",
                "Value": 100,
                "SecondKey": "SecondKey 1",
                "ThirdKey": "ThirdKey 1"
            }
        ]
    }
},
"Key 2": {
    "SecondKey 4": {
        "ThirdKey 1": [
            {
                "Key": "Key 2",
                "Value": 111,
                "SecondKey": "SecondKey 4",
                "ThirdKey": "ThirdKey 1"
            }
        ]
    },
    "SecondKey 2": {
        "ThirdKey 2": [
            {
                "Key": "Key 2",
                "Value": 400,
                "SecondKey": "SecondKey 2",
                "ThirdKey": "ThirdKey 2"
            }
        ]
    },
    "SecondKey 1": {
        "ThirdKey 2": [
            {
                "Key": "Key 2",
                "Value": 230,
                "SecondKey": "SecondKey 1",
                "ThirdKey": "ThirdKey 2"
            }
        ]
    }
}

我试过排序，但是排序把 Key 放在第二个位置并且打乱了下一个排序过程，而且它不起作用。

Answer 1

Python 字典是未排序的。您有几个选择。

使用将排序应用到标准字典的工具，示例:

import json
print json.dumps(thedict, indent=4, sort_keys=True)

使用维护字典条目创建顺序的类型:

from collections import OrderedDict
d = OrderedDict()
d[KEY] = VALUE
d[KEY][SUBKEY] = VALUE
etc.

或者最简单的方法是，按照您想要的顺序将它们添加到数组/列表的第一位。