On 7/10/2013 4:58 AM, Russel Walker wrote:
There is the name x and the class instance (the object) which exists somewhere in memory that x points to. self is just another name that points to the same object (not self in general but the argument passed to the self parameter when a method is called). However if the code inside the method reassigns self to some other object, it doesn't change the fact that x still refers to the original object. So self is just a local variable (an argument).
Yes, parameters *names* are the initial local names of the function. Calling the first parameter of instancemethods 'self' is a convention, not a requirement.
> The name self has no
relevance to to the name x other than the fact that they point to the same object. So reassigning self has no effect on x. But modifying the object that self points to, does affect x because it points to the same object. Is this correct?
Yes. Multiple names for one objects are 'aliases'. Being able to modify a object with multiple names in different namespaces is both a boon and bug bait.
So when you call x.somemethod() it's not passing x as the self
Python does not pass'x': it is 'call-by-object', not 'call-by-name'.
argument, it's actually passing the object that x points to as the self argument. And that object has know knowledge of the fact that x points to it, or does it?
Some objects (modules, classes, functions) have definition names (.__name__ attributes) that are used in their representations (as in tracebacks). But they have no knowledge of their namespace names.
-- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
