在检查内容时展平嵌套词典

时间:2014-07-14 08:39:34

标签: python json dictionary map flatten

我有这样的字典:

source = {

    'Section 1' : {
        'range'       : [0, 200],
        'template'    : 'ID-LOA-XXX',
        'nomenclature': True
    },

    'Section 2' : {
        'range'       : [201, 800],
        'template'    : 'ID-EPI-XXX',
        'nomenclature': False,
        'Subsection 1' : {
            'range'       : [0, 400],
            'template'    : 'ID-EPI-S1-XXX',
            'nomenclature': False,
            'Subsubsection 1' : {
                'range'       : [0, 400],
                'template'    : 'ID-EPI-S12-XXX',
                'nomenclature': False
            }
        },
        'Subsection 2' : {
            'range'       : [0, 400],
            'template'    : 'ID-EPI-S2-XXX',
            'nomenclature': False
        }
    }, 

    # etc.

}

从JSON文件加载。我想要“扁平化”。那到下面的字典:

target = {

    'Section 1' : {
        'range'       : [0, 200],
        'template'    : 'ID-LOA-XXX',
        'nomenclature': True,
        'location'    : './Section 1/'
    },

    'Section 2' : {
        'range'       : [201, 800],
        'template'    : 'ID-EPI-XXX',
        'nomenclature': False,
        'location'    : './Section 2/'
    },

    'Subsection 1' : {
        'range'       : [0, 400],
        'template'    : 'ID-EPI-S1-XXX',
        'nomenclature': False,
        'location'    : './Section 2/Subsection 1/'
    },

    'Subsubsection 1' : {
        'range'       : [0, 400],
        'template'    : 'ID-EPI-S12-XXX',
        'nomenclature': False,
        'location'    : './Section 2/Subsection 1/Subsubsection 1'
    },

    'Subsection 2' : {
        'range'       : [0, 400],
        'template'    : 'ID-EPI-S2-XXX',
        'nomenclature': False,
        'location'    : './Section 2/Subsection 2/'
    },

    # etc.

}

可以能够更改原始JSON文件的生成方式,但我不想去那里。

单词中的JSON文件:每个部分至少包含三个键,可能包含其他键。那些其他键被解释为当前部分中包含的子部分,每个键都是具有相同属性的dict。这种模式原则上可以无限深度地进行递归。

我还想执行一些断言:

  • 是否存在所有必填字段('range''template''nomenclature'
  • 必填字段的值通过某些断言

到目前为止,我只设法进行了这些检查:

import json

key_requirements = {
    "nomenclature": lambda x : isinstance(x, bool),
    "template"    : lambda x : isinstance(x, str)  and "X" in x,
    "range"       : lambda x : isinstance(x, list) and len(x)==2 and all([isinstance(y,int) for y in x]) and x[1] > x[0]
}

def checkSection(section):

    for key in section:
        if key not in key_requirements:            
            checkSection(section[key])

        elif not key_requirements[key]( section[key] ): 
            # error: assertion failed
            pass

        else:      
            # error: key not present
            pass

for key in source # json.load(open(myJsonFile))
    checkSection(data[key])

但是目前,没有多少咖啡能够让我想出一种高效,优雅,抒情的方式来将所需的转换编织到这个方案中......

有任何建议或想法吗?

3 个答案:

答案 0 :(得分:2)

问题需要递归遍历,除非你想要一些第三方库(是的,有解决方案),你需要一个简单的本地增长的递归遍历

NOte 路径语义可能与您的不同,因为我在Windows上

<强>实施

def flatten(source):
    target = {}
    def helper(src, path ='.', last_key = None):
        if last_key: 
            target[last_key] = {}
            target[last_key]['location'] = path
        for key, value in src.items():
            if isinstance(value, dict):
                helper(value, os.path.join(path, key), key)

            else:
                target[last_key][key] = value

    helper(source)
    return target

<强>输出

>>> pprint.pprint(source)
{'Section 1': {'nomenclature': True,
               'range': [0, 200],
               'template': 'ID-LOA-XXX'},
 'Section 2': {'Subsection 1': {'Subsubsection 1': {'nomenclature': False,
                                                    'range': [0, 400],
                                                    'template': 'ID-EPI-S12-XXX'},
                                'nomenclature': False,
                                'range': [0, 400],
                                'template': 'ID-EPI-S1-XXX'},
               'Subsection 2': {'nomenclature': False,
                                'range': [0, 400],
                                'template': 'ID-EPI-S2-XXX'},
               'nomenclature': False,
               'range': [201, 800],
               'template': 'ID-EPI-XXX'}}
>>> pprint.pprint(flatten(source))
{'Section 1': {'location': '\\Section 1',
               'nomenclature': True,
               'range': [0, 200],
               'template': 'ID-LOA-XXX'},
 'Section 2': {'location': '\\Section 2',
               'nomenclature': False,
               'range': [201, 800],
               'template': 'ID-EPI-XXX'},
 'Subsection 1': {'location': '\\Section 2\\Subsection 1',
                  'nomenclature': False,
                  'range': [0, 400],
                  'template': 'ID-EPI-S1-XXX'},
 'Subsection 2': {'location': '\\Section 2\\Subsection 2',
                  'nomenclature': False,
                  'range': [0, 400],
                  'template': 'ID-EPI-S2-XXX'},
 'Subsubsection 1': {'location': '\\Section 2\\Subsection 1\\Subsubsection 1',
                     'nomenclature': False,
                     'range': [0, 400],
                     'template': 'ID-EPI-S12-XXX'}}

答案 1 :(得分:1)

这适用于您的情况:

output = {}
for key, value in source.iteritems():
    item = {}
    for nested_key, nested_value in value.iteritems():
        if type(nested_value) == type({}):
            nested_item = {}
            for nested_key_2, nested_value_2 in nested_value.iteritems():
                nested_item[nested_key_2] = nested_value_2
            output[nested_key] = nested_item
        else:
            item[nested_key] = nested_value
    output[key] = item

答案 2 :(得分:0)

我最终得到了这个解决方案:

import os

key_requirements = {
    "nomenclature": lambda x : isinstance(x, bool),
    "template"    : lambda x : isinstance(x, str)  and "X" in x,
    "range"       : lambda x : isinstance(x, list) and len(x)==2 and all([isinstance(y,int) for y in x]) and x[1] > x[0]
}


def checkAndFlattenData(data):

    def merge_dicts(dict1,dict2):
        return dict(list(dict1.items()) + list(dict2.items()))


    def check_section(section, section_content):

        section_out = {
            'range'   : section_content['range'],
            'template': section_content['template'],
            'location': section
        }
        nested_section_out = {}

        for key,value in section_content.iteritems():

            if key not in key_requirements:
                if not isinstance(value,dict):
                    # error: invalid key
                    pass

                else:
                    nested_section_out[key], recurse_out = check_section(key,value)
                    nested_section_out = merge_dicts(nested_section_out, recurse_out)


            elif not key_requirements[key](value):
                print "ASSERTION FAILED!"# error: field assertion failed
                pass

        for key in nested_section_out:
            nested_section_out[key]['location'] = os.path.join(section, nested_section_out[key]['location'])

        return section_out, nested_section_out

    new_data = {}
    for key,value in data.iteritems():
        new_data[key], nested_data = check_section(key, value)
        new_data = merge_dicts(new_data, nested_data)

    for key,value in new_data.iteritems():
        new_data[key]['location'] = os.path.join('.', new_data[key]['location'])

    return new_data


target = checkAndFlattenData(source)

但是,我无法摆脱这种感觉,这可以做得更加pythonic(和/或更有效)...如果有人有任何建议,不要犹豫复制粘贴这个并在独立答案中做出改进,所以我可以接受。

相关问题