Python object initialization bug. Or am I misunderstanding how objects work?

Question

  1 import sys
  2 
  3 class dummy(object):
  4     def __init__(self, val):
  5         self.val = val
  6 
  7 class myobj(object):
  8     def __init__(self, resourc         


        

Answer 1

Your problem is that the default value is evaluated at function definition time. This means that the same list object is shared between instances. See the answer to this question for more discussion.