我试图将抓取的内容转换为数据操作列表,但出现以下错误:TypeError: 'NoneType' object is not callable
#! /usr/bin/python
from urllib import urlopen
from BeautifulSoup import BeautifulSoup
import os
import re
# Copy all of the content from the provided web page
webpage = urlopen("http://www.optionstrategist.com/calculators/free-volatility- data").read()
# Grab everything that lies between the title tags using a REGEX
preBegin = webpage.find('<pre>') # Locate the pre provided
preEnd = webpage.find('</pre>') # Locate the /pre provided
# Copy the content between the pre tags
voltable = webpage[preBegin:preEnd]
# Pass the content to the Beautiful Soup Module
raw_data = BeautifulSoup(voltable).splitline()