向模型添加反序列化接口导致错误

import json

class Model:
    def __init__(self, data):
        self.data = data

    @classmethod
    def from_json(cls, json_str):
        try:
            data = json.loads(json_str)
            # 验证数据格式
            if not isinstance(data, dict) or 'data' not in data:
                raise ValueError("Invalid data format")
            return cls(data['data'])
        except json.JSONDecodeError:
            raise ValueError("Invalid JSON format")

# 示例
json_str = '{"data": "example"}'
model = Model.from_json(json_str)

import hashlib

def verify_data_integrity(data, expected_hash):
    actual_hash = hashlib.sha256(data.encode()).hexdigest()
    return actual_hash == expected_hash

# 示例
data = '{"data": "example"}'
expected_hash = 'expected_hash_value'
if verify_data_integrity(data, expected_hash):
    model = Model.from_json(data)
else:
    raise ValueError("Data integrity check failed")

# 使用json模块进行安全的反序列化
import json

class Model:
    def __init__(self, data):
        self.data = data

    @classmethod
    def from_json(cls, json_str):
        try:
            data = json.loads(json_str)
            return cls(data['data'])
        except json.JSONDecodeError:
            raise ValueError("Invalid JSON format")

# 示例
json_str = '{"data": "example"}'
model = Model.from_json(json_str)

class Model:
    def __init__(self, data, version):
        self.data = data
        self.version = version

    @classmethod
    def from_json(cls, json_str):
        try:
            data = json.loads(json_str)
            if 'version' not in data or data['version'] != '1.0':
                raise ValueError("Version mismatch")
            return cls(data['data'], data['version'])
        except json.JSONDecodeError:
            raise ValueError("Invalid JSON format")

# 示例
json_str = '{"data": "example", "version": "1.0"}'
model = Model.from_json(json_str)