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

You should change

def __init__(self, resources=[]):
    self._resources = resources

to

def __init__(self, resources=None):
    if resources is None:
        resources = []
    self._resources = resources

and all will be better. This is a detail in the way default arguments are handled if they're mutable. There's some more information in the discussion section of this page.