静态方法如何访问Python中的类变量？

Question

这就是我的代码

class InviteManager():
    ALREADY_INVITED_MESSAGE = "You are already on our invite list"
    INVITE_MESSAGE = "Thank you! we will be in touch soon"

    @staticmethod
    @missing_input_not_allowed
    def invite(email):
        try:
            db.session.add(Invite(email))
            db.session.commit()
        except IntegrityError:
            return ALREADY_INVITED_MESSAGE
        return INVITE_MESSAGE

当我运行测试时，我明白了

NameError: global name 'INVITE_MESSAGE' is not defined

如何访问INVITE_MESSAGE内部的@staticmethod？

Answer 1

刚刚意识到，我需要@classmethod

class InviteManager():
    ALREADY_INVITED_MESSAGE = "You are already on our invite list"
    INVITE_MESSAGE = "Thank you! we will be in touch soon"

    @classmethod
    @missing_input_not_allowed
    def invite(cls, email):
        try:
            db.session.add(Invite(email))
            db.session.commit()
        except IntegrityError:
            return cls.ALREADY_INVITED_MESSAGE
        return cls.INVITE_MESSAGE

你可以看看here

Answer 2

您可以以InviteManager.INVITE_MESSAGE的形式访问它，但更清晰的解决方案是将静态方法更改为类方法：

@classmethod
@missing_input_not_allowed
def invite(cls, email):
    return cls.INVITE_MESSAGE

（或者，如果你的代码看起来很简单，你可以用一个模块中的一堆函数和常量替换整个类。模块是命名空间。）

Answer 3

尝试：

class InviteManager():
    ALREADY_INVITED_MESSAGE = "You are already on our invite list"
    INVITE_MESSAGE = "Thank you! we will be in touch soon"

    @staticmethod
    @missing_input_not_allowed
    def invite(email):
        try:
            db.session.add(Invite(email))
            db.session.commit()
        except IntegrityError:
            return InviteManager.ALREADY_INVITED_MESSAGE
        return InviteManager.INVITE_MESSAGE

InviteManager在它的静态方法的范围内。