Create a block diagram from a python class hierarchy using blockdiag

visualize.py

"""
Dependencies: pip install blockdiag
Run: python visualize.py
"""

from blockdiag import parser, builder, drawer

TEMPLATE = """
blockdiag {{ orientation = portrait
    {}
}}"""


def hierarchy(cls):
    parents = set(cls.__bases__) - {object}
    if parents:
        edges = zip(parents, [cls]*len(parents))
        for parent in parents:
            return edges + hierarchy(parent)
    return []


def generate_blockdiag_string(cls):
    return TEMPLATE.format('\n'.join(
        '{} -> {};'.format(s.__name__, t.__name__) for s, t in hierarchy(cls)))


def build_png(source):
    tree = parser.parse_string(source)
    diagram = builder.ScreenNodeBuilder.build(tree)
    draw = drawer.DiagramDraw('PNG', diagram, filename="foo.png")
    draw.draw()
    draw.save()


if __name__ == '__main__':
    class Closeable(object):
        pass

    class Clickable(object):
        pass

    class Widget(Closeable, Clickable):
        pass

    class Panel(Widget):
        pass

    build_png(generate_blockdiag_string(Panel))