优化Python模块动态属性的类型提示：从__getattr__到结构化配置

# payment_settings_class.py
from typing import Any

# 假设这是一个获取当前支付设置的函数，返回一个具有各种属性的对象
def get_current_payment_settings() -> Any:
    # 实际实现可能从数据库、配置文件或API获取
    class CurrentSettings:
        something: int = 100
        currency: str = "USD"
    return CurrentSettings()

class PaymentSettings:
    """
    通过@property提供只读支付设置。
    """
    _settings_cache: Any = None # 内部缓存，避免重复加载

    @property
    def something(self) -> int:
        if self._settings_cache is None:
            self._settings_cache = get_current_payment_settings()
        return getattr(self._settings_cache, 'something')

    @property
    def currency(self) -> str:
        if self._settings_cache is None:
            self._settings_cache = get_current_payment_settings()
        return getattr(self._settings_cache, 'currency')

    # 如果需要，可以添加更多只读属性

# 实例化配置类，供其他模块导入使用
payment_settings = PaymentSettings()

# src/another_file.py
from .payment_settings_class import payment_settings

print(payment_settings.something) # IDE和类型检查器能正确识别something为int
print(payment_settings.currency)  # IDE和类型检查器能正确识别currency为str
# payment_settings.something = 200 # 会报错，因为@property只定义了getter

# payment_settings_dataclass.py
from dataclasses import dataclass

# 假设这是获取支付设置的函数，返回字典或类似结构
def get_raw_payment_settings() -> dict:
    return {"something": 100, "currency": "USD", "is_test_mode": True}

@dataclass(frozen=True)
class PaymentSettings:
    """
    使用冻结数据类存储支付设置。
    """
    something: int
    currency: str
    is_test_mode: bool = False # 可以有默认值

# 从原始数据加载配置
raw_settings = get_raw_payment_settings()
payment_settings = PaymentSettings(**raw_settings)

# src/another_file.py
from .payment_settings_dataclass import payment_settings

print(payment_settings.something)     # 类型检查器识别为int
print(payment_settings.currency)      # 类型检查器识别为str
print(payment_settings.is_test_mode)  # 类型检查器识别为bool
# payment_settings.something = 200    # 会报错，因为PaymentSettings是冻结的

# payment_settings_pydantic.py
from pydantic import BaseModel, ConfigDict, Field

# 假设这是获取原始配置数据的函数
def get_raw_nested_payment_settings() -> dict:
    return {
        "general": {"mode": "live", "region": "US"},
        "limits": {"daily_limit": 5000, "transaction_fee": 0.02},
        "is_test_mode": False
    }

# 定义一个基础的不可变模型配置
class BaseImmutable(BaseModel):
    model_config = ConfigDict(frozen=True) # 使实例不可变

class GeneralSettings(BaseImmutable):
    mode: str
    region: str

class LimitsSettings(BaseImmutable):
    daily_limit: int = Field(..., ge=0) # 字段验证：大于等于0
    transaction_fee: float

class PaymentSettings(BaseImmutable):
    """
    使用Pydantic管理复杂且不可变的支付设置。
    """
    general: GeneralSettings
    limits: LimitsSettings
    is_test_mode: bool = False

# 从原始数据加载并验证配置
raw_settings = get_raw_nested_payment_settings()
payment_settings = PaymentSettings(**raw_settings)

# src/another_file.py
from .payment_settings_pydantic import payment_settings

print(payment_settings.general.mode)       # 类型检查器识别为str
print(payment_settings.limits.daily_limit) # 类型检查器识别为int
# payment_settings.is_test_mode = True     # 会报错，因为PaymentSettings是冻结的