Get all field names for dictionary in Python

Question

Is there a way to get all nested field names of Python dictionary?

For example:

Dictionary:

{
   "a": [
      {
         "b": {
            "c": [
               "f",
               "g"
            ]
         }
      }
   ]
}

Result:

'a[0].b.c[0]'
'a[0].b.c[1]'

You want the names of the fields or their index in the respective dictionary? — Devanshu Misra, Oct 09 '19 at 11:55
Possible duplicate of [How can I extract all values from a dictionary in Python?](https://stackoverflow.com/questions/7002429/how-can-i-extract-all-values-from-a-dictionary-in-python) — , Oct 09 '19 at 11:57
I don't think there's a built-in way to do it, but a simple recursive function should be able to traverse an arbitrarily deep dict or even a mixture of dicts and lists. Maybe this will help: https://stackoverflow.com/questions/6027558/flatten-nested-dictionaries-compressing-keys — gstukelj, Oct 09 '19 at 12:00
I think your use case is not generic. Hence you'll have to write your own code for that. — Ganesh Satpute, Oct 09 '19 at 12:40

Ajax1234 · Accepted Answer · 2019-10-09T14:48:42.390

You can use recursion with a generator:

def traverse(d, c = []):
  if isinstance(d, list):
    for i, a in enumerate(d):
      if not isinstance(a, (dict, list)):
        yield '.'.join(c+[f'[{i}]'])
      else:
        yield from traverse(a, c+[f'[{i}]'])
  elif isinstance(d, dict):
     for a, b in d.items():
        if not isinstance(b, (list, dict)):
           yield '.'.join(c+[a])
        else:
           yield from traverse(b, c+[a])


d = {'a': [{'b': {'c': ['f', 'g']}}]}
import re
print([re.sub('\.(?=\[)', '', i) for i in traverse(d)])

Output:

['a[0].b.c[0]', 'a[0].b.c[1]']

Get all field names for dictionary in Python

1 Answers1