Question

Possible Duplicate:
Auto-incrementing IDs for Class Instances

I want to something like the following Java class in Python:

public class MyObject {
    private static int ID = 0;
    private final int id;
    public MyObject() {
        id = ID++;
    }
}

In this Java code, every myObject will have id and there will be no way that two objects could have the same ID (it’s a one-threaded application).

Can I do something like this in Python?

Answer 1

In Python, you can just refer directly to the class attribute:

class MyObject(object):
    ID = 0

    def __init__(self):
       self.id = MyObject.ID = MyObject.ID + 1

Demo:

>>> class MyObject(object):
...     ID = 0
...     def __init__(self):
...        self.id = MyObject.ID = MyObject.ID + 1
... 
>>> MyObject().id
1
>>> MyObject().id
2
>>> MyObject().id
3
>>> MyObject.ID
3