List all instances of a class

[andrewtrench]

I would like to be able to create a list of all instances of a class. Another post here described how to do it by appending to a list during the __init__ routine but since I am a real Python newbie (and even more of a newbie to classes) I was hoping someone could post a simple code example to show a real world example of this. Thanks in advance.

[Gribouillis]

Well, here is an example

class Thingy(object):
    instances = []

    def __init__(self):
        self.instances.append(self)

def waste_time_and_memory():
    t = Thingy()

for i in range(5):
    waste_time_and_memory()

print Thingy.instances

""" My output -->
[<__main__.Thingy object at 0x7f0581777c50>, <__main__.Thingy object at 0x7f0581777c90>, <__main__.Thingy object at 0x7f0581777cd0>, <__main__.Thingy object at 0x7f0581777d10>, <__main__.Thingy object at 0x7f0581777d50>]
"""

The main problem is that Thingy objects are immortal unless you empty the list periodically.

[andrewtrench]

Brilliant. That's just what I was after. So much easier to understand to actually see the code. Thanks for taking the time to help me.