import re


def IsHtml(data):
  """Return True if data is HTML, False otherwise.

  Args:
    data: str Data to check.

  Returns:
    bool True if data is HTML, False otherwise.
  """
  # Remove banners and XML header. Convert to lower case for easy search.
  data = ''.join(data.split('\n')).lower()
  pattern = re.compile('<html>.*?<body.*?>.*?</body>.*?</html>')
  if pattern.findall(data):
    return True
  else:
    return False