serialobj 0.8.1

简单类型和继承

让我们定义一个非常基本的 Person 类型，它定义了两个字符串字段：

class Person(SerialObject):
    __fields__ = {
        'name': str,
        'job': str
    }

现在我们可以简单地将与 json 兼容的数据反序列化为它，和/或将其实例序列化为类似 json 的结构：

>>> person_data = {
...     'name': 'Bob',
...     'job': 'lumberjack'
... }
>>> bob = Person.deserialize(person_data)
>>> bob.name
'Bob'
>>> bob.job
'lumberjack'
>>> bob.serialize()
{'job': 'lumberjack', 'name': 'Bob'}

当然，还有更多。让我们将Person子类化，例如定义一个TeamMate，它会覆盖job字段以使其成为dict并添加一个新的str字段：role。

class TeamMate(Person):
    __fields__ = {
        'role': str,
        'job': dict
    }

当然这是一个愚蠢的例子，但这让我们可以证明继承SerialObject类允许继承、覆盖和专门化结构定义：

>>> bob2 = TeamMate.deserialize(teammate_data)
>>> bob2.name
'Bob'
>>> bob2.job
{'all night': 'sleep', 'all day': 'work'}
>>> bob2.serialize()
{'role': 'lumberjack', 'name': 'Bob', 'job': {'all night': 'sleep', 'all day': 'work'}}

它还允许我们证明结构实际上是根据模型检查 的：让我们尝试使用不兼容的Person模型反序列化我们的teammate_data。

>>> Person.deserialize(teammate_data)
Traceback (most recent call last):
  File "<input>", line 1, in <module>
    Person.deserialize(teammate_data)
  File "/home/arnaud/work/serialobj/serialobj.py", line 242, in deserialize
    for key, val in data.items() if key in cls.__fields__
  File "/home/arnaud/work/serialobj/serialobj.py", line 242, in <dictcomp>
    for key, val in data.items() if key in cls.__fields__
  File "/home/arnaud/work/serialobj/serialobj.py", line 86, in deserialize
    .format(self.cls_.__name__, data))
serialobj.InvalidTypeError: Expected str, got {'all night': 'sleep', 'all day': 'work'}

是不是开始变得有趣了？

对象列表

让我们稍微调味。如果我想将字段定义为字符串列表怎么办？

好吧，这有一些糖：

class Task(SerialObject):
    __fields__ = {
        'title': str,
        'description': str,
        'checklist': [str]
    }

你自己看：

>>> data = {
...     'title': 'timber some wood',
...     'description': '',
...     'checklist': [
...         'some wood is timbered',
...         'the lumberjack is okay',
...         'he sleeps all night and works all day'
...     ]
... }
>>> tsk = Task.deserialize(data)
>>> tsk.checklist
['some wood is timbered', 'the lumberjack is okay', 'he sleeps all night and works all day']
>>> tsk.checklist.append("... and that's it")
>>> pprint(tsk.serialize())
{'checklist': ['some wood is timbered',
               'the lumberjack is okay',
               'he sleeps all night and works all day',
               "... and that's it"],
 'description': '',
 'title': 'timber some wood'}

变得花哨

当然，所有这些都是定义任意复杂 JSON-API 结构的基础构建块：

class Team(SerialObject):
    __fields__ = {
        'name': str,
        'manager': TeamMate,
        'members': [TeamMate],
        'backlog': [Task]
    }


COMPLEX_DATA = {
    'name': "The good ol' lumberjacks",
    'manager': {
        'name': 'Bob',
        'role': 'Be okay'
    },
    'members': [
        {
            'name': 'Jack',
            'role': 'sleep all night'
        },
        {
            'name': 'Barry',
            'role': 'work all day',
        }],
    'backlog': [
        {
            'title': 'timber some wood',
            'description': '',
            'checklist': [
                'some wood is timbered',
                'the lumberjack is okay',
                'he sleeps all night and works all day'
            ]
        }]
    }

开始了：

>>> team = Team.deserialize(COMPLEX_DATA)
>>> team.manager.name
'Bob'
>>> team.manager
<__console__.TeamMate object at 0x7f34edd2c9a8>
>>> team.backlog[0]
<__console__.Task object at 0x7f34edd9b7c8>
>>> team.backlog[0].title
'timber some wood'
>>> pprint(team.serialize())
{'backlog': [{'checklist': ['some wood is timbered',
                            'the lumberjack is okay',
                            'he sleeps all night and works all day'],
              'description': '',
              'title': 'timber some wood'}],
 'manager': {'name': 'Bob', 'role': 'Be okay'},
 'members': [{'name': 'Jack', 'role': 'sleep all night'},
             {'name': 'Barry', 'role': 'work all day'}],
 'name': "The good ol' lumberjacks"}