在Python中展平嵌套的JSON API字典

问题描述

我收到有关使用以下代码收集的距离矩阵的以下json响应:

import requests
import json

payload = {
    "origins": [{"latitude": 54.6565153,"longitude": -1.6802816},{"latitude": 54.6365153,"longitude": -1.6202816}],#surgery
    "destinations": [{"latitude": 54.6856522,"longitude": -1.2183634},{"latitude": 54.5393295,"longitude": -1.2623914},"longitude": -1.2623914}],#oa - up to 625 entries
    "travelMode": "driving","startTime": "2014-04-01T11:59:59+01:00","timeUnit": "second"
}
headers = {"Content-Length": "497","Content-Type": "application/json"}
paramtr = {"key": "INSERT_KEY_HERE"}
r = requests.post('https://dev.virtualearth.net/REST/v1/Routes/DistanceMatrix',data = json.dumps(payload),params = paramtr,headers = headers)
data = r.json()["resourceSets"][0]["resources"][0]

并且正在尝试展平:

destinations.latitude,destinations。经度,origins.latitude, origins.longitude,departmentTime,destinationIndex,originIndex, totalWalkDuration,travelDistance,travelDuration

来自:

    {'__type': 'DistanceMatrix:http://schemas.microsoft.com/search/local/ws/rest/v1','destinations': [{'latitude': 54.6856522,'longitude': -1.2183634},{'latitude': 54.5393295,'longitude': -1.2623914},'longitude': -1.2623914}],'errorMessage': 'Request completed.','origins': [{'latitude': 54.6565153,'longitude': -1.6802816},{'latitude': 54.6365153,'longitude': -1.6202816}],'results': [{'departureTime': '/Date(1396349159000-0700)/','destinationIndex': 0,'originIndex': 0,'totalWalkDuration': 0,'travelDistance': 38.209,'travelDuration': 3082},{'departureTime': '/Date(1396349159000-0700)/','destinationIndex': 1,'travelDistance': 40.247,'travelDuration': 2708},'destinationIndex': 2,'originIndex': 1,'travelDistance': 34.857,'travelDuration': 2745},'travelDistance': 36.895,'travelDuration': 2377},'travelDuration': 2377}]}

我目前取得的最好成绩是:

json_normalize(outtie,record_path="results",meta="origins")

但是其中包含嵌套的起点和终点,因此拒绝附加。我还尝试删除该类型以查看它是否有所不同,并尝试了max_level =和record_prefix ='_',但无济于事。

解决方法

  • 我认为这不是flatten_json的适当问题,但是,它对于构造不太周到的JSON对象很有用。
  • list中的destinations对应于list中的results,这意味着当它们标准化后,它们将具有相同的索引。
  • 可以正确整理数据框,因为它们将具有相应的索引。
# create a dataframe for results and origins
res_or = pd.json_normalize(data,record_path=['results'],meta=[['origins']])

# create a dataframe for destinations
dest = pd.json_normalize(data,record_path=['destinations'],record_prefix='dest_')

# normalize the origins column in res_or
orig = pd.json_normalize(res_or.origins).rename(columns={'latitude': 'origin_lat','longitude': 'origin_long'})

# concat the dataframes
df = pd.concat([res_or,orig,dest],axis=1).drop(columns=['origins'])

# display(df)
                departureTime  destinationIndex  originIndex  totalWalkDuration  travelDistance  travelDuration  origin_lat  origin_long  dest_latitude  dest_longitude
0  /Date(1396349159000-0700)/                 0            0                  0          38.209            3082   54.656515    -1.680282      54.685652       -1.218363
1  /Date(1396349159000-0700)/                 1            0                  0          40.247            2708   54.656515    -1.680282      54.539330       -1.262391
2  /Date(1396349159000-0700)/                 2            0                  0          40.247            2708   54.656515    -1.680282      54.539330       -1.262391

更新新示例数据

  • 记录包含destinationsorigins的索引,因此很容易为每个键创建一个单独的数据框,然后再.merge个数据框。
    • origdest的索引对应于destinationIndex中的originsIndexresults
# create three separate dataframe
results = pd.json_normalize(data,record_path=['results'])
dest = pd.json_normalize(data,record_prefix='dest_')
orig = pd.json_normalize(data,record_path=['origins'],record_prefix='orig_')

# merge them at the appropriate location
df = pd.merge(results,dest,left_on='destinationIndex',right_index=True)
df = pd.merge(df,left_on='originIndex',right_index=True)

# display(df)
                departureTime  destinationIndex  originIndex  totalWalkDuration  travelDistance  travelDuration  dest_latitude  dest_longitude  orig_latitude  orig_longitude
0  /Date(1396349159000-0700)/                 0            0                  0          38.209            3082      54.685652       -1.218363      54.656515       -1.680282
1  /Date(1396349159000-0700)/                 1            0                  0          40.247            2708      54.539330       -1.262391      54.656515       -1.680282
2  /Date(1396349159000-0700)/                 2            0                  0          40.247            2708      54.539330       -1.262391      54.656515       -1.680282
3  /Date(1396349159000-0700)/                 0            1                  0          34.857            2745      54.685652       -1.218363      54.636515       -1.620282
4  /Date(1396349159000-0700)/                 1            1                  0          36.895            2377      54.539330       -1.262391      54.636515       -1.620282
5  /Date(1396349159000-0700)/                 2            1                  0          36.895            2377      54.539330       -1.262391      54.636515       -1.620282
,

我之前遇到过类似的情况,我得到的最好的是创建一个 OrderedDict 的递归函数,然后我在其中循环遍历,就是这样。

def flatten(data,sep="_"):
    import collections

    obj = collections.OrderedDict()

    def recurse(temp,parent_key=""):
        if isinstance(temp,list):
            for i in range(len(temp)):
                recurse(temp[i],parent_key + sep + str(i) if parent_key else str(i))
        elif isinstance(temp,dict):
            for key,value in temp.items():
                recurse(value,parent_key + sep + key if parent_key else key)
        else:
            obj[parent_key] = temp

    recurse(data)
    return obj

当您遍历它时,您的数据将看起来像这样

for key,value in flatten(a).items():
    print(key,value)

destinations_0_latitude 54.6856522
destinations_0_longitude -1.2183634
destinations_1_latitude 54.5393295
destinations_1_longitude -1.2623914
destinations_2_latitude 54.5393295
destinations_2_longitude -1.2623914

我使用分隔符的原因是,它为您提供了可扩展性,因此您可以使用

key.split("_")

['destinations','0','latitude'] 54.6856522
['destinations','longitude'] -1.2183634

之后,您可以轻松修改语句,例如

if key.split("_")[2] = "latitude":
    do something...

if key.endswith("latitude"):
    do something...

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