Extracts csv show data from epguides html source.

    Parameters
    ----------
      html : string
        Block of html text

    Returns
    ----------
       string
        Show data extracted from html text in csv format.

def _ExtractDataFromShowHtml(self, html):
    """
    Extracts csv show data from epguides html source.

    Parameters
    ----------
      html : string
        Block of html text

    Returns
    ----------
       string
        Show data extracted from html text in csv format.
    """
    htmlLines = html.splitlines()
    for count, line in enumerate(htmlLines):
      if line.strip() == r'<pre>':
        startLine = count+1
      if line.strip() == r'</pre>':
        endLine = count

    try:
      dataList = htmlLines[startLine:endLine]
      dataString = '\n'.join(dataList)
      return dataString.strip()
    except:
      raise Exception("Show content not found - check EPGuides html formatting")