Graph visualization

cm3tree.visualize.py

def visualize(node, edges, done = [], depth = ()):
    # Edge = namedtuple('Edge', 'source, dest')
    paths = [e for e in edges if getattr(e, 'source') == node]
    for edge in paths:
        for d in depth:
            if not d:
                print '│',
            else:
                print ' ',
        # is current path last in source's paths
        is_last = paths.index(edge) == len(paths)-1
        if is_last:
            symbol = '└ '
        else:
            symbol = '├ '
        print symbol+str(edge.dest),
        if edge.dest in done:
            print '*' # next destination's path has been already printed
        else:
            print
            done.append(edge.dest)
            if len(depth) < 15: # limit for better readability
                visualize(edge.dest, edges, done, depth + (is_last,))