Поиск путей в направленном нецикличном графе

main.py

'''
example of graph in input.json

{
  "start": "1",
  "end": "12",
  "nodes": {
    "1": ["2", "3"],
    "2": ["4", "7"],
    "3": ["5", "11"],
    "4": ["6"],
    "5": ["9"],
    "6": ["10"],
    "7": ["10", "3"],
    "9": ["11"], 
    "10": ["12"],
    "11": ["12"]
  }
}

'''

import json

def findPath(start, end, graph, path, nodes):
  if start == end:
    print(path)
  else:
    for node in graph[start]:
      findPath(node, end, graph, path+'-'+node, nodes)

with open('input.json', 'r') as myfile:
    data=myfile.read()

obj = json.loads(data)

findPath(obj["start"], obj["end"], obj["nodes"], obj["start"], {})