I have been trying to normalize a very nested json file I will later analyze. What I am struggling with is how to go more than one level deep to normalize.

我浏览了pandas.io.json.json_normalize个文档,因为它做的正是我想要它做的事情.

我已经能够对其中的一部分进行规范化,现在我明白了字典是如何工作的,但我仍然没有做到这一点.

With below code I am able to get only the first level.

import json
import pandas as pd
from pandas.io.json import json_normalize

with open('authors_sample.json') as f:
    d = json.load(f)

raw = json_normalize(d['hits']['hits'])

authors = json_normalize(data = d['hits']['hits'], 
                         record_path = '_source', 
                         meta = ['_id', ['_source', 'journal'], ['_source', 'title'], 
                                 ['_source', 'normalized_venue_name']
                                 ])

I am trying to 'dig' into the 'authors' dictionary with below code, but the record_path = ['_source', 'authors'] throws me TypeError: string indices must be integers. As far as I understand json_normalize the logic should be good, but I still don't quite understand how to dive into a json with dict vs list.

I even went through this simple example.

authors = json_normalize(data = d['hits']['hits'], 
                         record_path = ['_source', 'authors'], 
                         meta = ['_id', ['_source', 'journal'], ['_source', 'title'], 
                                 ['_source', 'normalized_venue_name']
                                 ])

下面是json文件的一部分(5条记录).

{u'_shards': {u'failed': 0, u'successful': 5, u'total': 5},
 u'hits': {u'hits': [{u'_id': u'7CB3F2AD',
    u'_index': u'scibase_listings',
    u'_score': 1.0,
    u'_source': {u'authors': None,
     u'deleted': 0,
     u'description': None,
     u'doi': u'',
     u'is_valid': 1,
     u'issue': None,
     u'journal': u'Physical Review Letters',
     u'link': None,
     u'meta_description': None,
     u'meta_keywords': None,
     u'normalized_venue_name': u'phys rev lett',
     u'pages': None,
     u'parent_keywords': [u'Chromatography',
      u'Quantum mechanics',
      u'Particle physics',
      u'Quantum field theory',
      u'Analytical chemistry',
      u'Quantum chromodynamics',
      u'Physics',
      u'Mass spectrometry',
      u'Chemistry'],
     u'pub_date': u'1987-03-02 00:00:00',
     u'pubtype': None,
     u'rating_avg_weighted': 0,
     u'rating_clarity': 0.0,
     u'rating_clarity_weighted': 0.0,
     u'rating_innovation': 0.0,
     u'rating_innovation_weighted': 0.0,
     u'rating_num_weighted': 0,
     u'rating_reproducability': 0,
     u'rating_reproducibility_weighted': 0.0,
     u'rating_versatility': 0.0,
     u'rating_versatility_weighted': 0.0,
     u'review_count': 0,
     u'tag': [u'mass spectra', u'elementary particles', u'bound states'],
     u'title': u'Evidence for a new meson: A quasinuclear NN-bar bound state',
     u'userAvg': 0.0,
     u'user_id': None,
     u'venue_name': u'Physical Review Letters',
     u'views_count': 0,
     u'volume': None},
    u'_type': u'listing'},
   {u'_id': u'7AF8EBC3',
    u'_index': u'scibase_listings',
    u'_score': 1.0,
    u'_source': {u'authors': [{u'affiliations': [u'Punjabi University'],
       u'author_id': u'780E3459',
       u'author_name': u'munish puri'},
      {u'affiliations': [u'Punjabi University'],
       u'author_id': u'48D92C79',
       u'author_name': u'rajesh dhaliwal'},
      {u'affiliations': [u'Punjabi University'],
       u'author_id': u'7D9BD37C',
       u'author_name': u'r s singh'}],
     u'deleted': 0,
     u'description': None,
     u'doi': u'',
     u'is_valid': 1,
     u'issue': None,
     u'journal': u'Journal of Industrial Microbiology & Biotechnology',
     u'link': None,
     u'meta_description': None,
     u'meta_keywords': None,
     u'normalized_venue_name': u'j ind microbiol biotechnol',
     u'pages': None,
     u'parent_keywords': [u'Nuclear medicine',
      u'Psychology',
      u'Hydrology',
      u'Chromatography',
      u'X-ray crystallography',
      u'Nuclear fusion',
      u'Medicine',
      u'Fluid dynamics',
      u'Thermodynamics',
      u'Physics',
      u'Gas chromatography',
      u'Radiobiology',
      u'Engineering',
      u'Organic chemistry',
      u'High-performance liquid chromatography',
      u'Chemistry',
      u'Organic synthesis',
      u'Psychotherapist'],
     u'pub_date': u'2008-04-04 00:00:00',
     u'pubtype': None,
     u'rating_avg_weighted': 0,
     u'rating_clarity': 0.0,
     u'rating_clarity_weighted': 0.0,
     u'rating_innovation': 0.0,
     u'rating_innovation_weighted': 0.0,
     u'rating_num_weighted': 0,
     u'rating_reproducability': 0,
     u'rating_reproducibility_weighted': 0.0,
     u'rating_versatility': 0.0,
     u'rating_versatility_weighted': 0.0,
     u'review_count': 0,
     u'tag': [u'flow rate',
      u'operant conditioning',
      u'packed bed reactor',
      u'immobilized enzyme',
      u'specific activity'],
     u'title': u'Development of a stable continuous flow immobilized enzyme reactor for the hydrolysis of inulin',
     u'userAvg': 0.0,
     u'user_id': None,
     u'venue_name': u'Journal of Industrial Microbiology & Biotechnology',
     u'views_count': 0,
     u'volume': None},
    u'_type': u'listing'},
   {u'_id': u'7521A721',
    u'_index': u'scibase_listings',
    u'_score': 1.0,
    u'_source': {u'authors': [{u'author_id': u'7FF872BC',
       u'author_name': u'barbara eileen ryan'}],
     u'deleted': 0,
     u'description': None,
     u'doi': u'',
     u'is_valid': 1,
     u'issue': None,
     u'journal': u'The American Historical Review',
     u'link': None,
     u'meta_description': None,
     u'meta_keywords': None,
     u'normalized_venue_name': u'american historical review',
     u'pages': None,
     u'parent_keywords': [u'Social science',
      u'Politics',
      u'Sociology',
      u'Law'],
     u'pub_date': u'1992-01-01 00:00:00',
     u'pubtype': None,
     u'rating_avg_weighted': 0,
     u'rating_clarity': 0.0,
     u'rating_clarity_weighted': 0.0,
     u'rating_innovation': 0.0,
     u'rating_innovation_weighted': 0.0,
     u'rating_num_weighted': 0,
     u'rating_reproducability': 0,
     u'rating_reproducibility_weighted': 0.0,
     u'rating_versatility': 0.0,
     u'rating_versatility_weighted': 0.0,
     u'review_count': 0,
     u'tag': [u'social movements'],
     u'title': u"Feminism and the women's movement : dynamics of change in social movement ideology, and activism",
     u'userAvg': 0.0,
     u'user_id': None,
     u'venue_name': u'The American Historical Review',
     u'views_count': 0,
     u'volume': None},
    u'_type': u'listing'},
   {u'_id': u'7DAEB9A4',
    u'_index': u'scibase_listings',
    u'_score': 1.0,
    u'_source': {u'authors': [{u'author_id': u'0299B8E9',
       u'author_name': u'fraser j harbutt'}],
     u'deleted': 0,
     u'description': None,
     u'doi': u'',
     u'is_valid': 1,
     u'issue': None,
     u'journal': u'The American Historical Review',
     u'link': None,
     u'meta_description': None,
     u'meta_keywords': None,
     u'normalized_venue_name': u'american historical review',
     u'pages': None,
     u'parent_keywords': [u'Superconductivity',
      u'Nuclear fusion',
      u'Geology',
      u'Chemistry',
      u'Metallurgy'],
     u'pub_date': u'1988-01-01 00:00:00',
     u'pubtype': None,
     u'rating_avg_weighted': 0,
     u'rating_clarity': 0.0,
     u'rating_clarity_weighted': 0.0,
     u'rating_innovation': 0.0,
     u'rating_innovation_weighted': 0.0,
     u'rating_num_weighted': 0,
     u'rating_reproducability': 0,
     u'rating_reproducibility_weighted': 0.0,
     u'rating_versatility': 0.0,
     u'rating_versatility_weighted': 0.0,
     u'review_count': 0,
     u'tag': [u'iron'],
     u'title': u'The iron curtain : Churchill, America, and the origins of the Cold War',
     u'userAvg': 0.0,
     u'user_id': None,
     u'venue_name': u'The American Historical Review',
     u'views_count': 0,
     u'volume': None},
    u'_type': u'listing'},
   {u'_id': u'7B3236C5',
    u'_index': u'scibase_listings',
    u'_score': 1.0,
    u'_source': {u'authors': [{u'author_id': u'7DAB7B72',
       u'author_name': u'richard m freeland'}],
     u'deleted': 0,
     u'description': None,
     u'doi': u'',
     u'is_valid': 1,
     u'issue': None,
     u'journal': u'The American Historical Review',
     u'link': None,
     u'meta_description': None,
     u'meta_keywords': None,
     u'normalized_venue_name': u'american historical review',
     u'pages': None,
     u'parent_keywords': [u'Political Science', u'Economics'],
     u'pub_date': u'1985-01-01 00:00:00',
     u'pubtype': None,
     u'rating_avg_weighted': 0,
     u'rating_clarity': 0.0,
     u'rating_clarity_weighted': 0.0,
     u'rating_innovation': 0.0,
     u'rating_innovation_weighted': 0.0,
     u'rating_num_weighted': 0,
     u'rating_reproducability': 0,
     u'rating_reproducibility_weighted': 0.0,
     u'rating_versatility': 0.0,
     u'rating_versatility_weighted': 0.0,
     u'review_count': 0,
     u'tag': [u'foreign policy'],
     u'title': u'The Truman Doctrine and the origins of McCarthyism : foreign policy, domestic politics, and internal security, 1946-1948',
     u'userAvg': 0.0,
     u'user_id': None,
     u'venue_name': u'The American Historical Review',
     u'views_count': 0,
     u'volume': None},
    u'_type': u'listing'}],
  u'max_score': 1.0,
  u'total': 36429433},
 u'timed_out': False,
 u'took': 170}

推荐答案

在Pandas 的例子(下图)中,括号是什么意思?是否有逻辑可以遵循,以便更深入地使用[].[...]

result = json_normalize(data, 'counties', ['state', 'shortname', ['info', 'governor']])

['state', 'shortname', ['info', 'governor']]值中的每个字符串或字符串列表都是要包含的元素的路径,in addition to the selected rows.第二个参数json_normalize()参数(record_path,在文档示例中设置为'counties')告诉函数如何从输入数据 struct 中 Select 组成输出行的元素,meta个路径添加了更多元数据,这些元数据将包含在每一行中.如果愿意的话,可以将这些视为数据库中的表连接.

The input for the US States documentation example has two dictionaries in a list, and both of these dictionaries have a counties key that references another list of dicts:

>>> data = [{'state': 'Florida',
...          'shortname': 'FL',
...         'info': {'governor': 'Rick Scott'},
...         'counties': [{'name': 'Dade', 'population': 12345},
...                      {'name': 'Broward', 'population': 40000},
...                      {'name': 'Palm Beach', 'population': 60000}]},
...         {'state': 'Ohio',
...          'shortname': 'OH',
...          'info': {'governor': 'John Kasich'},
...          'counties': [{'name': 'Summit', 'population': 1234},
...                       {'name': 'Cuyahoga', 'population': 1337}]}]
>>> pprint(data[0]['counties'])
[{'name': 'Dade', 'population': 12345},
 {'name': 'Broward', 'population': 40000},
 {'name': 'Palm Beach', 'population': 60000}]
>>> pprint(data[1]['counties'])
[{'name': 'Summit', 'population': 1234},
 {'name': 'Cuyahoga', 'population': 1337}]

Between them there are 5 rows of data to use in the output:

>>> json_normalize(data, 'counties')
         name  population
0        Dade       12345
1     Broward       40000
2  Palm Beach       60000
3      Summit        1234
4    Cuyahoga        1337

然后,meta参数将一些活动next的元素命名为这counties个列表,然后将这些元素单独合并.对于这meta个元素,前data[0]个字典中的值分别为('Florida', 'FL', 'Rick Scott'),对于data[1]个元素,值分别为('Ohio', 'OH', 'John Kasich'),因此您可以看到附加到来自同一顶级字典的counties行的值,分别重复了3次和2次:

>>> data[0]['state'], data[0]['shortname'], data[0]['info']['governor']
('Florida', 'FL', 'Rick Scott')
>>> data[1]['state'], data[1]['shortname'], data[1]['info']['governor']
('Ohio', 'OH', 'John Kasich')
>>> json_normalize(data, 'counties', ['state', 'shortname', ['info', 'governor']])
         name  population    state shortname info.governor
0        Dade       12345  Florida        FL    Rick Scott
1     Broward       40000  Florida        FL    Rick Scott
2  Palm Beach       60000  Florida        FL    Rick Scott
3      Summit        1234     Ohio        OH   John Kasich
4    Cuyahoga        1337     Ohio        OH   John Kasich

So, if you pass in a list for the meta argument, then each element in the list is a separate path, and each of those separate paths identifies data to add to the rows in the output.

your个示例JSON中,只有几个嵌套列表可以用第一个参数提升,就像示例中的'counties'个一样.该数据 struct 中唯一的示例是嵌套的'authors'个键;您必须提取每个['_source', 'authors']个路径,然后可以从父对象添加其他键来增加这些行.

The second meta argument then pulls in the _id key from the outermost objects, followed by the nested ['_source', 'title'] and ['_source', 'journal'] nested paths.

record_path参数以authors个列表为起点,如下所示:

>>> d['hits']['hits'][0]['_source']['authors']   # this value is None, and is skipped
>>> d['hits']['hits'][1]['_source']['authors']
[{'affiliations': ['Punjabi University'],
  'author_id': '780E3459',
  'author_name': 'munish puri'},
 {'affiliations': ['Punjabi University'],
  'author_id': '48D92C79',
  'author_name': 'rajesh dhaliwal'},
 {'affiliations': ['Punjabi University'],
  'author_id': '7D9BD37C',
  'author_name': 'r s singh'}]
>>> d['hits']['hits'][2]['_source']['authors']
[{'author_id': '7FF872BC',
  'author_name': 'barbara eileen ryan'}]
>>> # etc.

下面是几行:

>>> json_normalize(d['hits']['hits'], ['_source', 'authors'])
           affiliations author_id          author_name
0  [Punjabi University]  780E3459          munish puri
1  [Punjabi University]  48D92C79      rajesh dhaliwal
2  [Punjabi University]  7D9BD37C            r s singh
3                   NaN  7FF872BC  barbara eileen ryan
4                   NaN  0299B8E9     fraser j harbutt
5                   NaN  7DAB7B72   richard m freeland

然后,我们可以使用第三个meta参数添加更多列,如_id_source.title_source.journal,使用['_id', ['_source', 'journal'], ['_source', 'title']]:

>>> json_normalize(
...     data['hits']['hits'],
...     ['_source', 'authors'],
...     ['_id', ['_source', 'journal'], ['_source', 'title']]
... )
           affiliations author_id          author_name       _id   \
0  [Punjabi University]  780E3459          munish puri  7AF8EBC3  
1  [Punjabi University]  48D92C79      rajesh dhaliwal  7AF8EBC3
2  [Punjabi University]  7D9BD37C            r s singh  7AF8EBC3
3                   NaN  7FF872BC  barbara eileen ryan  7521A721
4                   NaN  0299B8E9     fraser j harbutt  7DAEB9A4
5                   NaN  7DAB7B72   richard m freeland  7B3236C5

                                     _source.journal
0  Journal of Industrial Microbiology & Biotechno...
1  Journal of Industrial Microbiology & Biotechno...
2  Journal of Industrial Microbiology & Biotechno...
3                     The American Historical Review
4                     The American Historical Review
5                     The American Historical Review

                                       _source.title  \
0  Development of a stable continuous flow immobi...
1  Development of a stable continuous flow immobi...
2  Development of a stable continuous flow immobi...
3  Feminism and the women's movement : dynamics o...
4  The iron curtain : Churchill, America, and the...
5  The Truman Doctrine and the origins of McCarth...

Json相关问答推荐

使用Jolt库对多个数组进行嵌套循环

如何编写MongoDB查询以返回数组数组

如何使用JQ打印每个根级对象键一行?

过go 24小时内判断员事件的EventBridge事件模式

Golang返回的JSON顶级字段是可变的.如何在 struct 中使用

Allof Indide的JSON模式之一

如何在VB6中将字符串转换或解码为可读格式?

用巨大的值更新SQL Server中的nvarchar(max)

jq 对特定键进行过滤并将值整理到单个 csv 单元格中

如何在 jq 中按 IP 地址排序?

从 oracle 数据库中的 json blob 打印值

使用 TypeScript 接口时如何修复未定义错误?

使用 JQ 从文件中删除重复的 JSON 块

从ruby中的json获取特定的键值

哪个更好:Json 或 XML (PHP)

IE8 原生 JSON.parse 错误导致堆栈溢出

如何将 LinkedHashMap 转换为自定义 java 对象?

[__NSCFNumber 长度]:发送到实例 UITableView 的无法识别的 Select 器

如何安装 json gem - 无法构建 gem 原生扩展(mac 10.10)

MVC JsonResult camelCase 序列化