Property Graph Basics

This example builds a tiny property graph and shows label indexes, outgoing neighbor lookup, two-hop traversal, frontier extraction, and probability transfer over edge properties.

Python

import json
from tonggraph import Graph

graph = Graph()
alice = graph.add_node(
    "alice",
    labels=["Person"],
    properties={"name": "Alice", "active": True},
)
bob = graph.add_node("bob", labels=["Person"], properties={"name": "Bob"})
claim = graph.add_node("claim:1", labels=["Claim"], properties={"topic": "graph"})

graph.add_edge(alice, bob, "KNOWS", properties={"probability": 0.8, "weight": 2.0})
graph.add_edge(bob, claim, "SUPPORTS", properties={"probability": 0.5, "weight": 1.0})

result = {
    "node_count": graph.node_count(),
    "person_nodes": graph.nodes_with_label("Person"),
    "alice_neighbors": graph.neighbors(alice),
    "two_hop_from_alice": graph.k_hop(alice, 2),
    "support_frontier": graph.frontier([alice], 2),
    "probability_transfer": {
        str(k): v for k, v in sorted(graph.propagate({alice: 1.0}, 2).items())
    },
}

print(json.dumps(result, indent=2, sort_keys=True))

Output:

{
  "alice_neighbors": [
    1
  ],
  "node_count": 3,
  "person_nodes": [
    0,
    1
  ],
  "probability_transfer": {
    "0": 1.0,
    "1": 0.8,
    "2": 0.4
  },
  "support_frontier": [
    2
  ],
  "two_hop_from_alice": [
    1,
    2
  ]
}