Tree - Depth first search

Depth_first_search.py

def recursive_dfs(graph, source,path = []):
       if source not in path:
           path.append(source)
           if source not in graph:
               # leaf node, backtrack
               return path
           for neighbour in graph[source]:
               path = recursive_dfs(graph, neighbour, path)
       return path


# Adjacency List graph
graph = {"A":["B","C", "D"],
           "B":["E"],
           "C":["F","G"],
           "D":["H"],
           "E":["I"],
           "F":["J"]}
path = recursive_dfs(graph, "A")
print(" ".join(path))