python dict用.来获取属性, 不用[]或者get

object_dict.py

# tornado.util.ObjectDict
# Makes a dictionary behave like an object, with attribute-style access.
import typing
_ObjectDictBase = typing.Dict[str, typing.Any]

class ObjectDict(_ObjectDictBase):
  """Makes a dictionary behave like an object, with attribute-style access.
  """
  def __getattr__(self, name):
    # type: (str) -> Any
    try:
      return self[name]
    except KeyError:
      raise AttributeError(name)
      
  def __setattr__(self, name, value):
    # type: (str, Any) -> None
    self[name] = value
    
# >>> a = ObjectDict()
# >>> isinstance(a, dict)   # True
# >>> a.k1 = 'v1'
# >>> a.k2 = 2
# >>> a						# {'k1': 'v1', 'k2': 2}