Py-gato

Paraphrasing the website:
Gato – the Graph Animation Toolbox – is software [toolkit] which visualizes
algorithms on graphs.
– Graphs are mathematical objects consisting of vertices, and edges
connecting pairs of vertices.
– Algorithms might find a shortest path – the fastest route – or a minimal
spanning tree or solve one of other interesting problems on graphs:
maximal-flow, weighted and non-weighted matching and min-cost flow.
– Visualisation means linking cause – the statements of an algorithm -
immediately to an effect – changes to the graph the algorithm has as its
input – by terms of blinking, changing colors and other visual effects.