def retrieve_subgraph(G, query):
    query = query.lower()

    context = []

    for node in G.nodes(data=True):

        node_name = node[0].lower()

        if (
            query in node_name
            or node_name in query
        ):

            for neighbor in G.neighbors(node[0]):

                edge = G[node[0]][neighbor]

                context.append(
                    f"{node[0]} --{edge.get('relation','related_to')}--> {neighbor}"
                )

    return "\n".join(context)

#test
from graph_builder import load_graph

if __name__ == "__main__":

    G = load_graph()

    result = retrieve_subgraph(
        G,
        "Python"
    )

    print(result)