更新我知道在正常情况下我可以使用 property 来做到这一点.关键部分是我将 SQLAlchemy 与这些类一起使用.我不完全理解 SQLAlchemy 是如何发挥其魔力的，但我怀疑自己创建和覆盖这些属性可能会导致不稳定和/或不可预测的结果. 解决方案 您可以使用 @validates() 装饰器在 SQLAlchemy 类中添加数据验证.来自文档 - 简单验证器:属性验证器可以引发异常，停止改变属性值的过程，或者可以将给定的值更改为不同的值.from sqlalchemy.orm import 验证类电子邮件地址(基础):__表名__ = '地址'id = 列(整数，primary_key=True)电子邮件 = 列(字符串)@validates('email')def validate_email(self, key, address):# 你可以使用断言，比如# 在地址中声明'@'# 或引发异常:如果@"不在地址中:raise ValueError('电子邮件地址必须包含@符号.')退货地址Is there a way to perform validation on an object after (or as) the properties are set but before the session is committed?For instance, I have a domain model Device that has a mac property. I would like to ensure that the mac property contains a valid and sanitized mac value before it is added to or updated in the database.It looks like the Pythonic approach is to do most things as properties (including SQLAlchemy). If I had coded this in PHP or Java, I would probably have opted to create getter/setter methods to protect the data and give me the flexibility to handle this in the domain model itself.public function mac() { return $this->mac; }public function setMac($mac) { return $this->mac = $this->sanitizeAndValidateMac($mac);}public function sanitizeAndValidateMac($mac) { if ( ! preg_match(self::$VALID_MAC_REGEX) ) { throw new InvalidMacException($mac); } return strtolower($mac);}What is a Pythonic way to handle this type of situation using SQLAlchemy?(While I'm aware that validation and should be handled elsewhere (i.e., web framework) I would like to figure out how to handle some of these domain specific validation rules as they are bound to come up frequently.)UPDATEI know that I could use property to do this under normal circumstances. The key part is that I am using SQLAlchemy with these classes. I do not understand exactly how SQLAlchemy is performing its magic but I suspect that creating and overriding these properties on my own could lead to unstable and/or unpredictable results. 解决方案 You can add data validation inside your SQLAlchemy classes using the @validates() decorator.From the docs - Simple Validators: An attribute validator can raise an exception, halting the process of mutating the attribute’s value, or can change the given value into something different.from sqlalchemy.orm import validatesclass EmailAddress(Base): __tablename__ = 'address' id = Column(Integer, primary_key=True) email = Column(String) @validates('email') def validate_email(self, key, address): # you can use assertions, such as # assert '@' in address # or raise an exception: if '@' not in address: raise ValueError('Email address must contain an @ sign.') return address 这篇关于有没有办法透明地对 SQLAlchemy 对象执行验证?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！
