accessor_dict.py

class AccessorDict(dict):
  def __getitem__(self, key):
    """Handle access like foo['bar']
    Wrap any raw dicts in new AccessorDict instances
    """
    out = super(AccessorDict, self).__getitem__(key)
    if isinstance(out, dict):
      out = AccessorDict(out)
    return out

  def __getattr__(self, attr, default=None):
    """Handle access like foo.bar
    Wrap any raw dicts in new AccessorDict instances
    """
    if attr in self.__dict__.keys():
      return self.__dict__[attr]
    else:
      try:
        out = self[attr]
        if isinstance(out, dict):
          out = AccessorDict(out)
        return out
      except KeyError:
        return default

  def __setattr__(self, attr, val):
    raise NotImplementedError, "cannot write to AccessorDict instances!"


# make a nested dict structure (generally json->dict makes these messes)
d = {
    'x': {
      'y': {
        'z': 'IT WORKS!'
      }
    }
  }

# wrap the dict
ad = AccessorDict(d)
# you can use dotted notation to decend the keys
print ad.x.y.z
# you can still use regular notation too
print ad['x']['y']['z']
# you can also mix them
print ad.x.y['z']
print ad['x'].y.z
# you can also use get with them for defaults
print ad.x.y.get('z', 'default') # key present
print ad.x.y.get('zzz', 'default') # key absent
# you cannot write to keys at any level
ad.x.y.z = 20