python - BeautifulSoup - python - table 刮

Question

尝试使用 beautiful soup 从网站上抓取表格以解析数据。我将如何通过它的标题来解析它？到目前为止，我什至无法打印整个表格。提前致谢。

代码如下:

import urllib2
from bs4 import BeautifulSoup

optionstable = "http://www.barchart.com/options/optdailyvol?type=stocks"
page = urllib2.urlopen(optionstable)
soup = BeautifulSoup(page, 'lxml')

table = soup.find("div", {"class":"dataTables_wrapper","id": "options_wrapper"})

table1 = table.find_all('table')

print table1

Answer 1

需要模仿ajax请求获取表格数据:

import requests
from time import time

optionstable = "http://www.barchart.com/options/optdailyvol?type=stocks"


params = {"type": "stocks",
          "dir": "desc",
          "_": str(time()),
          "f": "base_symbol,type,strike,expiration_date,bid,ask,last,volume,open_interest,volatility,timestamp",
          "sEcho": "1",
          "iDisplayStart": "0",
          "iDisplayLength": "100",
          "iSortCol_0": "7",
          "sSortDir_0": "desc",
          "iSortingCols": "1",
          "bSortable_0": "true",
          "bSortable_1": "true",
          "bSortable_2": "true",
          "bSortable_3": "true",
          "bSortable_4": "true",
          "bSortable_5": "true",
          "bSortable_6": "true",
          "bSortable_7": "true",
          "bSortable_82": "true",
          "bSortable_9": "true",
          "bSortable_10": "true",
          "sortby": "Volume"}

然后获取传递参数:

js = requests.get("http://www.barchart.com/option-center/getData.php", params=params).json()

这给了你:

{u'aaData': [[u'<a href="/quotes/BAC">BAC</a>', u'Call', u'16.00', `u'12/16/16', u'0.89', u'0.90', u'0.91', u'52,482', u'146,378', u'0.26', u'01:43'], [u'<a href="/quotes/ETE">ETE</a>', u'Call', u'20.00', u'01/20/17', u'0.38', u'0.41', u'0.40', u'40,785', u'72,011', u'0.42', u'01:27'], [u'<a href="/quotes/BAC">BAC</a>', u'Call', u'15.00', u'10/21/16', u'1.34', u'1.36', u'1.33', u'35,663', u'90,342', u'0.35', u'01:44'], [u'<a href="/quotes/COTY">COTY</a>', u'Put', u'38.00', u'10/21/16', u'15.00', u'15.30', u'15.10', u'32,321', u'242,382', u'1.24', u'01:44'], [u'<a href="/quotes/COTY">COTY</a>', u'Call', u'38.00', u'10/21/16', u'0.00', u'0.05', u'0.01', u'32,320', u'256,589', u'1.34', u'01:44'], [u'<a href="/quotes/WFC">WFC</a>', u'Put', u'40.00', u'10/21/16', u'0.01', u'0.03', u'0.02', u'32,121', u'37,758', u'0.39', u'01:43'], [u'<a href="/quotes/WFC">WFC</a>', u'Put', u'40.00', u'11/18/16', u'0.16', u'0.17', u'0.16', u'32,023', u'8,789', u'0.30', u'01:44']..................

你可以传递更多的参数，如果你在 XHR 选项卡下查看 chrome 工具中的请求，你可以看到所有的params，上面的是获得结果所需的最低限度。有很多，所以我不会将它们全部张贴在这里，让您自己弄清楚如何影响结果。

如果您遍历 js[u'aaData']，您可以看到每个子列表，其中每个条目对应于如下列:

#base_symbol,type,strike,expiration_date,bid,ask,last,volume,open_interest,volatility,timestamp

[u'<a href="/quotes/AAPL">AAPL</a>', u'Call', u'116.00', u'10/14/16', u'1.36', u'1.38', u'1.37', u'21,812', u'7,258', u'0.23', u'10/10/16']

因此，如果您想根据某些条件过滤行，例如 strike > 15:

for d in filter(lambda row: float(row[2]) > 15, js[u'aaData']):
    print(d)

您可能还会发现 pandas 很有用，稍微整理一下我们就可以创建一个漂亮的 df:

# extract base_symbol text
for v in js[u'aaData']:
    v[0] = BeautifulSoup(v[0]).a.text


import  pandas as pd
cols = "base_symbol,type,strike,expiration_date,bid,ask,last,volume,open_interest,volatility,timestamp"

df = pd.DataFrame(js[u'aaData'],
    columns=cols.split(","))

print(df.head(5))

这给了你一个很好的 df 来工作:

  base_symbol  type strike expiration_date    bid    ask   last  volume  \
0         BAC  Call  16.00        12/16/16   0.89   0.90   0.91  52,482   
1         ETE  Call  20.00        01/20/17   0.38   0.41   0.40  40,785   
2         BAC  Call  15.00        10/21/16   1.34   1.36   1.33  35,663   
3        COTY   Put  38.00        10/21/16  15.00  15.30  15.10  32,321   
4        COTY  Call  38.00        10/21/16   0.00   0.05   0.01  32,320   

  open_interest volatility timestamp  
0       146,378       0.26  10/10/16  
1        72,011       0.42  10/10/16  
2        90,342       0.35  10/10/16  
3       242,382       1.24  10/10/16  
4       256,589       1.34  10/10/16  

您可能只想更改 dtypes df["strike"] = df["strike"].astype(float) 等。