Traversing through nested dictionary tree

Question

Below is the tree as a dictionary:

tree = {'X1': {0: {'X2': {0: 0, 1: {'X3': {0: 1, 1: 0}}}}, 1: {'X3': {0: 1, 1: 0}}}}

How do I traverse through this tree in python and print only the nodes? Eg X1, X2...

This might be of use: https://stackoverflow.com/questions/3860813/recursively-traverse-multidimensional-dictionary-dimension-unknown — cs95, Feb 08 '18 at 20:42
Possible duplicate of [recursively traverse multidimensional dictionary, dimension unknown](https://stackoverflow.com/questions/3860813/recursively-traverse-multidimensional-dictionary-dimension-unknown) — Mihayl, Feb 08 '18 at 21:39

score 1 · Answer 1 · answered Feb 08 '18 at 21:14

You need to step through each level of the dict, printing out all matching keys, and then calling the same function (recursion) if the value is a nested dict:

tree = {'X1': {0: {'X2': {0: 0, 1: {'X3': {0: 1, 1: 0}}}}, 1: {'X3': {0: 1, 1: 0}}}}

def recurse(d):
  for x, v in d.items():
    if str(x).startswith('X'):
        print(x)
    if isinstance(v, dict):
      recurse(v)

recurse(tree)

Traversing through nested dictionary tree

1 Answers1