old_contents: import sys, subprocess
  
  def run_dot(dot):
      from IPython.display import SVG
      dot = dot.encode('utf8')
      process = subprocess.Popen(['dot', '-Tsvg'], 
                                 stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE, 
                                 stderr=subprocess.PIPE)
      out, err = process.communicate(dot)
      if err:
          raise Exception(err)
      return SVG(out.decode('utf8'))
  
new_contents: import sys, subprocess
  import re
  
  def run_dot(dot):
      from IPython.display import SVG
      dot = dot.encode('utf8')
      process = subprocess.Popen(['dot', '-Tsvg'], 
                                 stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE, 
                                 stderr=subprocess.PIPE)
      out, err = process.communicate(dot)
      if err:
          raise Exception(err)
      out = out.decode('utf8')
      out = re.sub(r'<title>.*?</title>', '', out)
      return SVG(out)
  
subject: remove tooltips from svg output