python - Counting instances of a class?

Question

I've been cleaning up some code from a module I'm extending and I can't seem to find a way to Pythonify this code:

global_next_id = 1

class Obj:
  def __init__(self):
    global global_next_id
    self.id = global_next_id

    global_next_id += 1

This code uses a global id to keep track of instances of a class (I need the variable self.id internally as well, and it needs to be a number).

Can anyone suggest a way to Pythonify this code?

Answer 1

Try something like this:

from itertools import count

class Obj(object):
  _ids = count(0)

  def __init__(self):
    self.id = next(self._ids)