get basic graph dependencies

get_dependencies.py

def get_dependencies(node, edges_list, depth=0):
    if depth > len(edges_list):
        raise Exception('Circular dependency somewhere.')
    seen_nodes = set()
    for from_node, to_node in edges_list:
        if from_node == node:
            seen_nodes.add(from_node)
            if to_node in seen_nodes:
                continue
            yield to_node
            nested_deps = []
            for to_dep in get_dependencies(to_node, edges_list, depth=depth+1):
                nested_deps.append(to_dep)
            if nested_deps:
                for nd in nested_deps:
                    yield nd
def test_get_dependencies():
    result = list(get_node_dependencies('a', (['a','b'],['b','d'], ['c','d'],['d','e'],)))
    expected = ['b', 'd', 'e']
    assert result == expected
test_get_dependencies()