code: def bookDF(symbol, token='', version=''):
      '''Book data
  
      https://iextrading.com/developer/docs/#book
      realtime during Investors Exchange market hours
  
      Args:
          symbol (string); Ticker to request
          token (string); Access token
          version (string); API version
  
      Returns:
          DataFrame: result
      '''
      x = book(symbol, token, version)
      df = _bookToDF(x)
      return df bookDF(symbol, token='', version=''):
      '''Book data
  
      https://iextrading.com/developer/docs/#book
      realtime during Investors Exchange market hours
  
      Args:
          symbol (string); Ticker to request
          token (string); Access token
          version (string); API version
  
      Returns:
          DataFrame: result
      '''
      x = book(symbol, token, version)
      df = _bookToDF(x)
      return df
docs: Book data
  
      https://iextrading.com/developer/docs/#book
      realtime during Investors Exchange market hours
  
      Args:
          symbol (string); Ticker to request
          token (string); Access token
          version (string); API version
  
      Returns:
          DataFrame: result