diagram_definition = (
    '\n   seqdiag {\n      browser  -> webserver [label = "GET /index.html"];\n      browser <- webserver;\n   }\n'
    )
tree = parser.parse_string(diagram_definition)
diagram = builder.ScreenNodeBuilder.build(tree)
draw = drawer.DiagramDraw('PNG', diagram, filename='diagram.png')
draw.draw()
generate uml sequence diagrams with python or perl