python数据抓取改变货币

Question

我正在尝试使用页面 https://coinmarketcap.com/currencies/bitcoin/historical-data/?start=20130428&end=20180216 中的以下脚本从 coinmarketcap.com 获取比特币和以太坊历史价格:

import requests
import xlwt
import traceback
import pandas as pd
import urllib.request as req
from bs4 import BeautifulSoup
from pandas import ExcelWriter

def process_data(data, coin, workbook):
  try:
    sheet = workbook.add_sheet(coin)
    soup = BeautifulSoup(data, 'lxml')
    table = soup.find_all('table')[0]

    df = pd.read_html(str(table))
    k = (df[0].to_json(orient='records'))
    import json
    resp = json.loads(k)
    # resp format: {'Date': 'Apr 28, 2013', 'Open': 135.3, 'High': 135.98, 'Low': 132.1, 'Close': 134.21, 'Volume': '-', 'Market Cap': 1500520000}
    lst = [[each['Date'], each['Open'], each['High'], each['Low'], each['Close'], each['Volume'], each['Market Cap']] for each in resp]

    for i, l in enumerate(lst):
      for j, col in enumerate(l):
        sheet.write(i, j, col)
  except Exception as e:
    print (e)
    print(traceback.print_exc())

coins = ['Bitcoin', 'Ethereum']

workbook = xlwt.Workbook(encoding='ascii')

if __name__ == '__main__':
    for each in coins:
      coin = each.lower()
      url = "https://coinmarketcap.com/currencies/"+ coin + "/historical-data/?start=20090428&end=20180207"
      print (url)
      try:
        a = requests.get(url)
        process_data(a.text, each, workbook)
      except Exception as e:
        print 'error in fetching data', coin
    workbook.save('cmc_data_f.xls')

脚本从页面获取 html 响应并写入 Excel 文件。问题是网页默认返回美元数据。我想要欧元数据。

网站上有一个下拉菜单可供选择多种货币。但是当我从 python 发送请求时，它默认返回美元。

有谁知道是否有办法从 coinmarketcap.com 请求欧元货币网页？

Answer 1

不，但您可以从页面中提取所需的数据，以匹配页面正在进行的转换。

在table = ...位之后，添加此行以获取汇率:

usd_per_eur = float(soup.find("div",{"id":"currency-exchange-rates"})['data-eur'])

然后调整循环代码，如下所示:

for i, l in enumerate(lst):
  for j, col in enumerate(l):
    if 0 < j < 5: # indices 1-4 of response contain USD values
        try:
            converted = float(col)/usd_per_eur
        except ValueError:
            pass
        else:
            col = str(round(converted,2))
    sheet.write(i, j, col)