This is a simple visualizer and simulator for Deterministic Finite Automatas. You can create multiple definitions and load them in the visualizer (like the examples), and then just feed whatever string you want to test against the automata.
It actually creates a pretty graph with its nodes arranged by physics forces. The next definition produces the image below:
# Σ
"sigma": ["0", "1"],
"Q": ["q0", "q1", "q2", "q3", "q4"],
"F": ["q4"],
# q -> state, a -> input
# δ : δ[q][a]
"delta": {
"q0": {"0": "q0", "1": "q1"},
"q1": {"0": "q2", "1": "q1"},
"q2": {"0": "q3", "1": "q1"},
"q3": {"0": "q0", "1": "q4"},
"q4": {"0": "q2", "1": "q1"},
},