Python 序列化类并使用 JsonPickle 更改属性大小写

Question

使用 Python 和 JsonPickle，如何使用特定的大小写（例如 Camel Case、Pascal 等）序列化对象？下面的答案是手动完成的，但是寻找特定的 Jsonpickle 解决方案，因为它可以处理复杂的对象类型。

JSON 序列化一个类并使用 Python 更改属性大小写

/sf/answers/602986751/

class HardwareSystem:
    def __init__(self, vm_size):
        self.vm_size = vm_size
        self.some_other_thing = 42
        self.a = 'a'

def snake_to_camel(s):
    a = s.split('_')
    a[0] = a[0].lower()
    if len(a) > 1:
        a[1:] = [u.title() for u in a[1:]]
    return ''.join(a)

def serialise(obj):
    return {snake_to_camel(k): v for k, v in obj.__dict__.items()}

hp = HardwareSystem('Large')
print(json.dumps(serialise(hp), indent=4, default=serialise))

Answer 1

这是我的尝试。

from importlib import import_module
import inspect
import json
import jsonpickle
import re


def snake_to_camel(s):
    a = s.split('_')
    a[0] = a[0].lower()
    if len(a) > 1:
        a[1:] = [u.title() for u in a[1:]]
    return ''.join(a)

def camel_to_snake(s):
    snake = []
    snake_len = len(s)
    for idx, char in enumerate(s):
        snake.append(char.lower())
        if idx < snake_len - 1:
            if char.islower() and s[idx+1].isupper():
                snake.append('_')
    return ''.join(snake)

def debug_output(obj):
    output = '{}({})'
    attrs = [attr + '=' + repr(getattr(obj, attr)) for attr in vars(obj)]
    return output.format(obj.__class__.__name__, ', '.join(attrs))


class SoftwareSystem:
    def __init__(self):
        self.software_rating = 'Awesome!'
    
    # Making debug output friendly
    def __repr__(self):
        return debug_output(self)


class HardwareSystem:
    def __init__(self, vm_size):
        self.vm_size = vm_size
        self.some_other_thing = 42
        self.a = 'a'
    
    # Making debug output friendly
    def __repr__(self):
        return debug_output(self)


@jsonpickle.handlers.register(HardwareSystem, base=True)
@jsonpickle.handlers.register(SoftwareSystem, base=True)
class SystemHandler(jsonpickle.handlers.BaseHandler):
    def flatten(self, obj, data):
        for k, v in obj.__dict__.items():
            data[snake_to_camel(k)] = jsonpickle.encode(v)
        return data

    def restore(self, obj):
        # Gets reference to class
        # /sf/answers/3889189671/
        module_path, class_name = obj['py/object'].rsplit('.', 1)
        module = import_module(module_path)
        class_ = getattr(module, class_name)

        # Dealing with __init__ params (except first)
        params = inspect.getargs(class_.__init__.__code__)
        params = params.args[1:]

        # Preparing dict keys
        l_obj = {}
        for k, v in obj.items():
            l_obj[camel_to_snake(k)] = v

        # Instantiating constructor params
        data = {}
        for k, v in l_obj.items():
            if k in params:
                data[k] = v 
        result = class_(**data)

        # Setting other jsonpickled object attributes 
        for k, v in l_obj.items():
            if not k in params:
                setattr(result, k, v)

        return result


hw = HardwareSystem(100)
sw = SoftwareSystem()
hw.software_instance = sw
json_str = jsonpickle.encode(hw)
print(json_str)
decoded = jsonpickle.decode(json_str)
print(hw)

这有一些假设：

• 按照您的原始snake_to_camel函数，我提出了一个camel_to_snake解码，假设只有小写字母后的第一个大写字母会在 char 前面加上_（因此awesomeABC将转换为awesome_abc，因此如果您再次将其翻译回来，它将是错误的awesomeAbc）
• 上面的代码对之后添加的属性进行编码/解码__init__（参见hw.software_instance上面的示例）。
• 您可以嵌套对象。我只尝试过嵌套一个对象。
• 我添加了辅助debug_output/__repr__功能，您可以扔掉它们（或自定义:)）