Spherogram is a Python module for dealing with the kind of planar diagrams that arise in 3-dimensional topology, such as link and Heegaard diagrams. It a component of the larger SnapPy project.
While these functions appear to be internal, I'm aware of user code that relies on their output being lists. So in the interests of backwards compatibility, unfortunately I'm not going to merge this one.
changing some functions, previously returnings lists, to become iterators
possibly not very useful for some of them, but still nicer maybe