Python pandas json_normalize 如何

Question

我正在尝试创建一个 API，从 poloniex 获取历史数据，供我的神经网络用于学校项目的学习。

我得到一个json文件，但问题是poloinex_df是“空”，所有信息都在index/columnnames行中(图片相关，变量资源管理器)，我尝试以某种方式转置它，然后我一直在这里告诉你，panda 有这个功能。我阅读了文档，并在这里四处寻找答案，但没有找到我想要的东西。我想制作一个数据框，其中包含日期、打开、关闭、音量等索引以及相应的数据。我怎么做？现在我收到错误:

data_frame = json_normalize(poloinex_df, 'date' ,['high', 'low', 'open', 'close','volume','quoteVolume','weightedAverage'])

Traceback (most recent call last):

File "", line 1, in data_frame = json_normalize(poloinex_df, 'date' ,['high', 'low', 'open', 'close','volume','quoteVolume','weightedAverage'])

File "C:\ToolBox\Anaconda2\lib\site-packages\pandas\io\json.py", line 761, in json_normalize _recursive_extract(data, record_path, {}, level=0)

File "C:\ToolBox\Anaconda2\lib\site-packages\pandas\io\json.py", line 747, in _recursive_extract recs = _pull_field(obj, path[0])

File "C:\ToolBox\Anaconda2\lib\site-packages\pandas\io\json.py", line 698, in _pull_field result = result[spec]

TypeError: string indices must be integers, not str

变量资源管理器中下载数据的图片:

我必须遵循以下代码:

import chainer as chain
import pandas as pd
import numpy as np
from matplotlib import pylab
from pandas.io.json import json_normalize

def get_poloinex_data(s, a, b, c):

    import requests
    from pandas import DataFrame
    from io import StringIO

    url = 'https://poloniex.com/public?command=returnChartData'

    url += '&currencyPair=' + s #USDT for USD
    url += '&start=' + a
    url += '&end=' + b
    url += '&period=' + c

    csv = requests.get(url)

    if csv.ok:
        return DataFrame.from_csv(StringIO(csv.text), sep=',') #Separator here
    else:
        return None

params = {
    # specify stock
    "s": 'USDT_ETH',   # BTC_ETH, USDT_ETH stb

    # query data from
    'a': '1422230400',     # unix date stamp, 2015 jan 26 : 1422230400

    # query until
    'b': '1492905600',     # unix dates tamp, 2016 sep 23 : 1492905600

    # frequency
    'c': '14400'      # unix time stamp
}


poloinex_df = get_poloinex_data(**params)
data_frame = json_normalize(poloinex_df, 'date' ,['high', 'low', 'open', 'close','volume','quoteVolume','weightedAverage'])
#data_frame = json_normalize(poloinex_df.json())
#TransposedData = poloinex_df.transpose()
#data_frame = json_normalize(resp.json())

感谢您的帮助和见解

Answer 1

import pandas as pd
import requests

def get_poloinex_data(s, a, b, c):

    url = 'https://poloniex.com/public?command=returnChartData'

    url += '&currencyPair=' + s #USDT for USD
    url += '&start=' + a
    url += '&end=' + b
    url += '&period=' + c
    data = requests.get(url)

    return data.content

params = {
    # specify stock
    "s": 'USDT_ETH',   # BTC_ETH, USDT_ETH stb

    # query data from
    'a': '1422230400',     # unix date stamp, 2015 jan 26 : 1422230400

    # query until
    'b': '1492905600',     # unix dates tamp, 2016 sep 23 : 1492905600

    # frequency
    'c': '14400'      # unix time stamp
}

poloinex_df = get_poloinex_data(**params)
data_frame = pd.read_json(poloinex_df)