Question

假设我有一个名为School的类，它有一个名为createSchool的方法，它将创建一个新的School实例并替换现有实例（从中调用createSchool）...

伪代码如下：

class School(object):
    def __init__(self,a=None,b=None):
        self.a = a
        self.b = b

    def createSchool(self,schoolFile):
        #...code to parse schoolFile and extract a,b and create a dict 
        # called schoolDict
        newClass = School(**schoolDict)
        #This step replaces the old dict with the new one, thereby reassigning all 
        # attributes.
        self.__dict__ = newClass.__dict__

我的问题是我最终用现有实例的字典替换新创建的字典，这是最好的方法吗？

谢谢，
Sarith

Answer 1

我认为你可以使用@classmethod decorator

class School(object):
    def __init__(self,a=None,b=None):
        self.a = a
        self.b = b

    @classmethod
    def createSchool(cls,schoolFile):
        schoolDict = parse(schoolFile)
        newClass = School(**schoolDict)
        return newClass

Answer 2

更好的方法是不删除调用实例。相反，这应该表示为一种类方法

class School(object):
    def __init__(self,a=None,b=None):
        self.a = a
        self.b = b

    @classmethod
    def createSchool(cls, schoolFile):
        # code to parse schoolFile and extract a,b and create a dict called schoolDict
        ... 
        return cls(**schoolDict)

现在我们可以使用as：

school = School.createSchool(...)

从方法中重新创建/重新分配类的最合适方法是什么？

2 个答案: