[Q] Deepcopy with Python 2.2 ?

[Oliver Hofmann]

'lo everyone!

I've had a few problems with copying objects lately when they 
reference each other. My understanding is that deepcopy should 
take care of that due to the memo - dictionary; this does not 
seem to be the case. 

The following code works fine if Base does _not_ inherit 
from object. If it does the result is:

RuntimeError: maximum recursion depth exceeded

Any help would be appreciated!

Thanks,

     Oliver


---8<-----
import copy

class Base(object):
    def __init__(self):
        self.parent = None
        object.__init__(self)

class Hit(Base):
    def __init__(self):
        self.hsps = []
        Base.__init__(self)
    
class HSP(Base):
    def __init__(self):
        self.data = [1, 2, 3]
        Base.__init__(self)

def main():
    a = Hit()
    b = HSP()
    c = HSP()
    d = HSP()
    a.hsps.extend([b, c, d])
    b.parent = a
    c.parent = a
    d.parent = a

    z = copy.deepcopy(a)

if __name__ == '__main__':
    main()