How to convert a MultiDict to nested dictionary

Question

I would like to convert a POST from Webob MultiDict to nested dictionary. E.g.

So from a POST of:

'name=Kyle&phone.number=1234&phone.type=home&phone.number=5678&phone.type=work'

to a multidict;

[('name', 'Kyle'), ('phone.number', '1234'), ('phone.type', 'home'), ('phone.number', '5678'), ('phone.type', 'work')]

to a nested dictionary

{'name': 'Kyle',
 'phone': [
  {
    'number': '12345',
    'type': 'home',
  },{
    'number': '5678',
    'type': 'work',
  },

Any ideas?

EDIT

I ended up extracting the variable_decode method from the formencode package as posted by Will. The only change that was required is to make the lists explicit, E.g.

'name=Kyle&phone-1.number=1234&phone-1.type=home&phone-2.number=5678&phone-2.type=work'

Which is better for many reasons.

Answer 1

If you have formencode installed or can install it, checkout out their variabledecode module

Answer 2

I haven't had the time to test it and it's quite restrictive, but hopefully this will work (I'm only posting because it's been a while since you posted the question):

>>> def toList(s):
...     answer = []
...     L = s.split("&")
...     for i in L:
...             answer.append(tuple(i.split('=')))
...     return answer

>>> def toDict(L):
...     answer = {}
...     answer[L[0][0]] = L[0][1]
...     for i in L[1:]:
...             pk,sk = L[i][0].split('.')
...             if pk not in answer:
...                     answer[pk] = []
...             if sk not in answer[pk][-1]:
...                     answer[pk][sk] = L[i][1]
...             else:
...                     answer[pk].append({sk:L[i][1]})

If this is not 100%, it should at least get you on a good start.

Hope this helps