code: def render_output_pydot(self, dotdata, **kwargs):
          
          if not HAS_PYDOT:
              raise CommandError("You need to install pydot python module")
  
          graph = pydot.graph_from_dot_data(dotdata)
          if not graph:
              raise CommandError("pydot returned an error")
          if isinstance(graph, (list, tuple)):
              if len(graph) > 1:
                  sys.stderr.write("Found more then one graph, rendering only the first one.\n")
              graph = graph[0]
  
          output_file = kwargs['outputfile']
          formats = [
              'bmp', 'canon', 'cmap', 'cmapx', 'cmapx_np', 'dot', 'dia', 'emf',
              'em', 'fplus', 'eps', 'fig', 'gd', 'gd2', 'gif', 'gv', 'imap',
              'imap_np', 'ismap', 'jpe', 'jpeg', 'jpg', 'metafile', 'pdf',
              'pic', 'plain', 'plain-ext', 'png', 'pov', 'ps', 'ps2', 'svg',
              'svgz', 'tif', 'tiff', 'tk', 'vml', 'vmlz', 'vrml', 'wbmp', 'xdot',
          ]
          ext = output_file[output_file.rfind('.') + 1:]
          format_ = ext if ext in formats else 'raw'
          graph.write(output_file, format=format_)
docs: Render model data as image using pydot