Question

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

I’m trying to create a callable class which will take arguments, then return itself as an object.

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

My questions are, if I call this object like so:

newUserObject = User(submittedLoginName)

Will __init__ get called BEFORE __call__? Should __init__ get the argument or should I be moving the argument over to __call__ like

def __call__(self, loginName):

Answer 1

__call__ is only called on an instance that defines itself as callable.

__init__ is the initializer that provided an instance of the class

If you do something like

MyObject()() Then you are initliaizing THEN calling.

Using your own example

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.