如何获取 json 中某个键的所有值，而不仅仅是最后一组？

Question

The for loop only outputs the marketids for the last set of races of the json file. I think this is because of the if statement preceding the for loop. Anyone know how I can continue looping whilst keeping the if statement?

My code:

request1 = requests.get('https://betfair-data-supplier-prod.herokuapp.com/api/daily_racing_results?date=2020-01-02')
json1 = request1.json()
marketids = []
for market in json1:
    if market['raceType'] in ['R']:
        marketids.append(market["markets"][0]["marketId"])
print(marketids)

Output of code:

['166897895', '166892549', '166896013', '166892651', '166892683', '166897912']

Example of json1:

[{'venueName': 'Geelong',
  'raceDay': '2020-01-02 00:00:00',
  'country': 'AUS',
  'raceType': 'R',
  'meetingId': '29637049',
  'markets': [{'marketId': '166897895',
    'raceNo': '1',
    'startTime': '2020-01-02 02:00:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Port Water Bouy Mdn Plate',
    'nzToteEventId': '287012'},
   {'marketId': '166897897',
    'raceNo': '2',
    'startTime': '2020-01-02 02:30:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Portarlington Beach Motel Mdn',
    'nzToteEventId': '287013'},
   {'marketId': '166897899',
    'raceNo': '3',
    'startTime': '2020-01-02 03:00:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Flash Fabrications Mdn Plat3',
    'nzToteEventId': '287014'},
   {'marketId': '166897901',
    'raceNo': '4',
    'startTime': '2020-01-02 03:30:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Race With Empower Racing Mdn',
    'nzToteEventId': '287015'},
   {'marketId': '166897903',
    'raceNo': '5',
    'startTime': '2020-01-02 04:00:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Absolute Landscapes Mdn Plate',
    'nzToteEventId': '287016'},
   {'marketId': '166897905',
    'raceNo': '6',
    'startTime': '2020-01-02 04:30:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Ajk Builders (Bm64)',
    'nzToteEventId': '287017'},
   {'marketId': '166933411',
    'raceNo': '7',
    'startTime': '2020-01-02 05:00:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Batman Mgmt Bellarine Cup-Bm64',
    'nzToteEventId': '287018'},
   {'marketId': '166897909',
    'raceNo': '8',
    'startTime': '2020-01-02 05:30:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Gj Bradding Heating&Cool.-Bm58',
    'nzToteEventId': '287019'},
   {'marketId': '166897911',
    'raceNo': '9',
    'startTime': '2020-01-02 06:00:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Bayshore Electrical (Bm58)',
    'nzToteEventId': '287020'}]},
 {'venueName': 'Mount Barker',
  'raceDay': '2020-01-02 00:00:00',
  'country': 'AUS',
  'raceType': 'R',
  'meetingId': '29636945',
  'markets': [{'marketId': '166892549',
    'raceNo': '1',
    'startTime': '2020-01-02 05:17:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Happy New Year Mdn',
    'nzToteEventId': ''},
   {'marketId': '166892551',
    'raceNo': '2',
    'startTime': '2020-01-02 05:52:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Langton Mdn',
    'nzToteEventId': ''},
   {'marketId': '166892553',
    'raceNo': '3',
    'startTime': '2020-01-02 06:32:00',
    'marketStatus': 'CLOSED',
    'eventName': 'McDonald Hcp (C2)',
    'nzToteEventId': ''},
   {'marketId': '166892555',
    'raceNo': '4',
    'startTime': '2020-01-02 07:10:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Hicks Hcp (C2)',
    'nzToteEventId': ''},
   {'marketId': '166892557',
    'raceNo': '5',
    'startTime': '2020-01-02 07:45:00',
    'marketStatus': 'CLOSED',
    'eventName': 'Lowood (Bm58+)',
    'nzToteEventId': ''}]}]

Answer 1

request1 = requests.get('https://betfair-data-supplier-prod.herokuapp.com/api/daily_racing_results?date=2020-01-02')
json1 = request1.json()
marketids = []
for market in json1:
    if market['raceType'] in ['R']:
        for id in market['markets']:
            marketids.append(market["markets"][id]["marketId"])
print(marketids)

edit solution by @Sushanth

[i['marketId'] for v in request1.json() if v['raceType'] == 'R' for i in v['markets']]

Answer 2

Use pandas.json_normalize

• Normalize semi-structured JSON data into a flat table.
  • Fewer lines of code
  • All of the data is in an easily usable format.
• If you still want marketId in a list:
  • df.marketId.to_list()

Unpack markets

import pandas as pd
import requests

request1 = requests.get('https://betfair-data-supplier-prod.herokuapp.com/api/daily_racing_results?date=2020-01-02')

json1 = request1.json()

df = pd.json_normalize(json1, 'markets')

# display(df.head()
    marketId raceNo            startTime marketStatus                      eventName nzToteEventId
0  166897895      1  2020-01-02 02:00:00       CLOSED      Port Water Bouy Mdn Plate        287012
1  166897897      2  2020-01-02 02:30:00       CLOSED  Portarlington Beach Motel Mdn        287013
2  166897899      3  2020-01-02 03:00:00       CLOSED   Flash Fabrications Mdn Plat3        287014
3  166897901      4  2020-01-02 03:30:00       CLOSED   Race With Empower Racing Mdn        287015
4  166897903      5  2020-01-02 04:00:00       CLOSED  Absolute Landscapes Mdn Plate        287016

Unpack all the keys

df = pd.json_normalize(json1, 'markets', ['venueName', 'raceDay', 'raceType', 'meetingId'])

# display(df.head())
    marketId raceNo            startTime marketStatus                      eventName nzToteEventId venueName              raceDay raceType meetingId
0  166897895      1  2020-01-02 02:00:00       CLOSED      Port Water Bouy Mdn Plate        287012   Geelong  2020-01-02 00:00:00        R  29637049
1  166897897      2  2020-01-02 02:30:00       CLOSED  Portarlington Beach Motel Mdn        287013   Geelong  2020-01-02 00:00:00        R  29637049
2  166897899      3  2020-01-02 03:00:00       CLOSED   Flash Fabrications Mdn Plat3        287014   Geelong  2020-01-02 00:00:00        R  29637049
3  166897901      4  2020-01-02 03:30:00       CLOSED   Race With Empower Racing Mdn        287015   Geelong  2020-01-02 00:00:00        R  29637049
4  166897903      5  2020-01-02 04:00:00       CLOSED  Absolute Landscapes Mdn Plate        287016   Geelong  2020-01-02 00:00:00        R  29637049