python config_error ai_generated true

pydantic_core._pydantic_core.ValidationError: 1 个验证错误，实例已冻结，无法修改字段 name [类型=frozen_instance]

pydantic_core._pydantic_core.ValidationError: 1 validation error for User name Instance is frozen [type=frozen_instance, input_value='Bob', input_type=str]

ID: python/pydantic-immutable-frozen-assignment

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80%修复率
90%置信度
0证据数
2024-04-11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

模型声明了 model_config = ConfigDict(frozen=True)，因此构造后任何属性赋值都会引发 frozen_instance 错误。

English

The model was declared with model_config = ConfigDict(frozen=True), so any attribute assignment after construction raises a frozen_instance error.

generic

解决方案

  1. 95% 成功率 
    new_user = user.model_copy(update={'name': 'Bob'})
  2. 90% 成功率 
    class User(BaseModel):
    model_config = ConfigDict(frozen=False)  # default
    name: str

无效尝试

常见但无效的做法:

  1. 75% 失败

    Bypasses Pydantic's checks and produces an inconsistent model that violates __hash__ and equality guarantees.

  2. 85% 失败

    Corrupts the model's internal fields storage and can raise KeyError or produce an invalid state.