Question

我正在使用Pandas从API获取数据。 API以JSON格式返回数据。然而，json在数据帧中有一些我不想要的值。由于这些值，我无法为数据框分配索引。以下是格式。

{
"Success": true,
"message": "",
"result": [{"id":12312312, "TimeStamp":"2017-10-04T17:39:53.92","Quantity":3.03046306,},{"id": 2342344, "TimeStamp":"2017-10-04T17:39:53.92","Quantity":3.03046306,}]}

我只对＆＃34;结果感兴趣＆＃34;部分。一种方法是使用request.get(request_URL)导入json，然后在提取＆＃34;结果＆＃34;部分，将结果转换为数据帧。第二种方法是导入数据Pandas.read_json(JSON_URL)将返回的数据帧转换回json，然后提取＆＃34;结果＆＃34; part，将结果转换为数据帧。

还有其他办法吗？什么是最好的方法，为什么？感谢。

Answer 1

使用Extracting token value from the response ：

from pandas.io.json import json_normalize

df = json_normalize(json['result'])
print (df)

   Quantity               TimeStamp        id
0  3.030463  2017-10-04T17:39:53.92  12312312
1  3.030463  2017-10-04T17:39:53.92   2342344

也在这里工作：

df = pd.DataFrame(d['result'])
print (df)
   Quantity               TimeStamp        id
0  3.030463  2017-10-04T17:39:53.92  12312312
1  3.030463  2017-10-04T17:39:53.92   2342344

DatetimeIndex转换列json_normalize和to_datetime：

df['TimeStamp'] = pd.to_datetime(df['TimeStamp'])
df = df.set_index('TimeStamp')
print (df)

                         Quantity        id
TimeStamp                                  
2017-10-04 17:39:53.920  3.030463  12312312
2017-10-04 17:39:53.920  3.030463   2342344

编辑：

加载数据解决方案：

from urllib.request import urlopen
import json
from pandas.io.json import json_normalize

response = urlopen("https://bittrex.com/api/v1.1/public/getmarkethistory?market=BTC-ETC")
json_data = response.read().decode('utf-8', 'replace')

d = json.loads(json_data)
df = json_normalize(d['result'])
df['TimeStamp'] = pd.to_datetime(df['TimeStamp'])
df = df.set_index('TimeStamp')

print (df.head())
                          Quantity     Total  
TimeStamp                                     
2017-10-05 06:05:06.510   3.579201  0.010000  
2017-10-05 06:04:34.060  45.614760  0.127444  
2017-10-05 06:04:34.060   5.649898  0.015785  
2017-10-05 06:04:34.060   1.769847  0.004945  
2017-10-05 06:02:25.063   0.250000  0.000698

另一种解决方案：

df = pd.read_json('https://bittrex.com/api/v1.1/public/getmarkethistory?market=BTC-ETC')
df = pd.DataFrame(df['result'].values.tolist())
df['TimeStamp'] = pd.to_datetime(df['TimeStamp'])
df = df.set_index('TimeStamp')
print (df.head())

                          Quantity     Total  
TimeStamp                                     
2017-10-05 06:11:25.100   5.620957  0.015704  
2017-10-05 06:11:11.427  22.853546  0.063851  
2017-10-05 06:10:30.600   6.999213  0.019555  
2017-10-05 06:10:29.163  20.000000  0.055878  
2017-10-05 06:10:29.163   0.806039  0.002252

Answer 2

另一种解决方案，基于jezrael使用请求：

import requests
import pandas as pd

d = requests.get("https://bittrex.com/api/v1.1/public/getmarkethistory?market=BTC-ETC").json()
df = pd.DataFrame.from_dict(d['result'])
df['TimeStamp'] = pd.to_datetime(df['TimeStamp'])
df = df.set_index('TimeStamp')

df

Pandas.read_json（JSON_URL）

2 个答案: