python - __call__ 与 __init__ : Who gets the arguments? 谁先被调用？

Question

Possible Duplicate:
what is difference between init and call in python?

我正在尝试创建一个可调用类，它将接受参数，然后将其自身作为对象返回。

class User(object):
    def __init__(self, loginName, password):
        self.loginName = loginName

    def __call__(self):
        if self.login():
            return self
        return None

    def login(self):
        database = db.connection
        realUser = database.checkPassWord(self.loginName, self.password)
        return realUser

我的问题是，如果我像这样调用这个对象:

newUserObject = User(submittedLoginName)

威尔__init__在 __call__ 之前接到电话？应该__init__得到论点，或者我应该将论点转移到 __call__喜欢

def __call__(self, loginName):

Answer 1

__call__ 仅在将自身定义为可调用的实例上调用。

__init__ 是提供类实例的初始值设定项

如果你做了类似的事情

MyObject()() 然后您正在初始化 THEN 调用。

使用您自己的示例

class User(object):
    def __init__(self, loginName, password):
        self.loginName = loginName
        self.password = password

    def __call__(self):
        if self.login():
            return self
        return None

    def login(self):
        database = db.connection
        return database.checkPassWord(self.loginName, self.password)

a = User("me", "mypassword")
a = a() # a is now either None or an instance that is aparantly logged in.