我正在寻找一种优雅的方式来获得数据使用属性访问字典与一些嵌套的字典和列表(即javascript风格的对象语法)。
例如:
>>> d = {'a': 1, 'b': {'c': 2}, 'd': ["hi", {'foo': "bar"}]}
应该以这样的方式访问:
>>> x = dict2obj(d)
>>> x.a
1
>>> x.b.c
2
>>> x.d[1].foo
bar
我想，如果没有递归，这是不可能的，但是有什么更好的方法来获得字典的对象样式呢?
当前回答
有一个 名为namedtuple的集合助手，可以为你做这些:
from collections import namedtuple
d_named = namedtuple('Struct', d.keys())(*d.values())
In [7]: d_named
Out[7]: Struct(a=1, b={'c': 2}, d=['hi', {'foo': 'bar'}])
In [8]: d_named.a
Out[8]: 1
其他回答
我不满意那些被标记和点赞的答案，所以这里有一个简单而通用的解决方案，用于将json风格的嵌套数据结构(由字典和列表组成)转换为普通对象的层次结构:
# tested in: Python 3.8
from collections import abc
from typings import Any, Iterable, Mapping, Union
class DataObject:
def __repr__(self):
return str({k: v for k, v in vars(self).items()})
def data_to_object(data: Union[Mapping[str, Any], Iterable]) -> object:
"""
Example
-------
>>> data = {
... "name": "Bob Howard",
... "positions": [{"department": "ER", "manager_id": 13}],
... }
... data_to_object(data).positions[0].manager_id
13
"""
if isinstance(data, abc.Mapping):
r = DataObject()
for k, v in data.items():
if type(v) is dict or type(v) is list:
setattr(r, k, data_to_object(v))
else:
setattr(r, k, v)
return r
elif isinstance(data, abc.Iterable):
return [data_to_object(e) for e in data]
else:
return data
如果只是将dict赋值给一个空对象的__dict__呢?
class Object:
"""If your dict is "flat", this is a simple way to create an object from a dict
>>> obj = Object()
>>> obj.__dict__ = d
>>> d.a
1
"""
pass
当然，这在你嵌套的dict例子上失败了，除非你递归地遍历dict:
# For a nested dict, you need to recursively update __dict__
def dict2obj(d):
"""Convert a dict to an object
>>> d = {'a': 1, 'b': {'c': 2}, 'd': ["hi", {'foo': "bar"}]}
>>> obj = dict2obj(d)
>>> obj.b.c
2
>>> obj.d
["hi", {'foo': "bar"}]
"""
try:
d = dict(d)
except (TypeError, ValueError):
return d
obj = Object()
for k, v in d.iteritems():
obj.__dict__[k] = dict2obj(v)
return obj
你的例子列表元素可能是一个映射，一个(键，值)对的列表，像这样:
>>> d = {'a': 1, 'b': {'c': 2}, 'd': [("hi", {'foo': "bar"})]}
>>> obj = dict2obj(d)
>>> obj.d.hi.foo
"bar"
如果你想让它递归的话，在之前接受的答案所做的基础上。
class FullStruct:
def __init__(self, **kwargs):
for key, value in kwargs.items():
if isinstance(value, dict):
f = FullStruct(**value)
self.__dict__.update({key: f})
else:
self.__dict__.update({key: value})
你可以用我的方法来处理。
somedict= {"person": {"name": "daniel"}}
class convertor:
def __init__(self, dic: dict) -> object:
self.dict = dic
def recursive_check(obj):
for key, value in dic.items():
if isinstance(value, dict):
value= convertor(value)
setattr(obj, key, value)
recursive_check(self)
my_object= convertor(somedict)
print(my_object.person.name)
有一个 名为namedtuple的集合助手，可以为你做这些:
from collections import namedtuple
d_named = namedtuple('Struct', d.keys())(*d.values())
In [7]: d_named
Out[7]: Struct(a=1, b={'c': 2}, d=['hi', {'foo': 'bar'}])
In [8]: d_named.a
Out[8]: 1
