recursively diff two dicts

diff_dict_recur.py

def diff_dicts_recur(dict1, dict2, prefix=tuple()):
  """Takes the diff of two dicts, recursively."""
  for k, v in dict1.iteritems():
    if k not in dict2:
      # only in dict1
      yield ('-', prefix + (k,), v)
    else:
      w = dict2[k]
      if w != v: # in both, but different values
        if isinstance(w, dict) and isinstance(v, dict):
          for x in diff_dicts_recur(v, w, prefix + (k,)):
            yield x

        else:
          yield ('-', prefix + (k,), v)
          yield ('+', prefix + (k,), w)

  for k in dict2.keys():
    if k not in dict1:
      # only in dict2
      yield ('+', prefix + (k,), dict2[k])