python - 类设计: Last Modified

Question

我的类(class):

class ManagementReview:
    """Class describing ManagementReview Object.
    """

    # Class attributes
    id = 0
    Title = 'New Management Review Object'
    fiscal_year = ''
    region = ''
    review_date = ''
    date_completed = ''
    prepared_by = ''

    __goals = [] # List of <ManagementReviewGoals>.
    __objectives = [] # List of <ManagementReviewObjetives>.
    __actions = [] # List of <ManagementReviewActions>.
    __deliverables = [] # List of <ManagementReviewDeliverable>.
    __issues = [] # List of <ManagementReviewIssue>.

    __created = ''
    __created_by = ''
    __modified = ''
    __modified_by = ''

__modified 属性是等格式的日期时间字符串。我希望每次更新其他属性之一时，该属性自动更新为 datetime.now().isoformat() 。对于其他每个属性，我都有一个 setter ，例如:

def setObjectives(self,objectives):
    mro = ManagementReviewObjective(args)
    self.__objectives.append(mro)

那么，有没有比添加一行更简单的方法:

self.__modified = datetime.now().isoformat()

每个二传手？

谢谢! :)

Answer 1

要在 instance 属性被修改时更新 __modified(如您的 self.__objectives 示例)，您可以覆盖 __setattr__ .

例如，您可以将此添加到您的类(class)中:

def __setattr__(self, name, value):
    # set the value like usual and then update the modified attribute too
    self.__dict__[name] = value
    self.__dict__['__modified'] = datetime.now().isoformat()