python config_error ai_generated true

pydantic_core._pydantic_core.ValidationError: 1 个验证错误，实例已冻结 [type=frozen_instance]

pydantic_core._pydantic_core.ValidationError: 1 validation error for Settings api_key Instance is frozen [type=frozen_instance, input_value='new-key', input_type=str]

ID: python/pydantic-configerror-frozen-field-mutation

其他格式: JSON · Markdown 中文 · English
80%修复率
89%置信度
0证据数
2024-09-08首次发现

版本兼容性

版本状态引入弃用备注
2.x active — — —

根因分析

BaseSettings/BaseModel 声明了 model_config = ConfigDict(frozen=True)，代码在构造之后尝试给字段赋新值。

English

A BaseSettings/BaseModel was declared with model_config = ConfigDict(frozen=True), and code attempted to assign a new value to a field after construction.

generic

解决方案

  1. 95% 成功率 
    new_settings = settings.model_copy(update={'api_key': 'new-key'})
  2. 90% 成功率 
    class Settings(BaseSettings):
    model_config = ConfigDict(frozen=False)
    api_key: str

无效尝试

常见但无效的做法:

  1. 55% 失败

    Bypassing Pydantic's __setattr__ works at runtime but leaves the model's internal __pydantic_fields_set__ inconsistent and can break serialization.

  2. 90% 失败

    frozen models also block __delattr__, raising TypeError: cannot delete field.