PyUMLGraph is a Python debugger that produces UML diagrams by inspecting
running Python programs. The output is in Graphviz's dot language, and dot
can produce pictures in many popular formats, such as PNG, PDF, SVG, and
others. The UML diagrams can contain information about class inheritance
relationships, references to other classes, class methods and return types,
as well as class attributes and types.

WWW: http://adamfeuer.com/~adamf/software/PyUMLGraph/