Hi,
Would anyone be able to tell me why my function below is getting stuck
in infinite recusion?
Maybe I'm just tired and missing something obvious?
def replace_within_node(node,oldnode,newnode):
if node is oldnode:
return newnode
else:
for varname,value in node.__dict__.items():
node.__dict__[varname]=replace_within_node(value,oldnode,newnode)
return node
At the end of this email I pasted the whole text of the sample code in
case it would help to see it in context or maybe step through it?
--
Gregory Piñero
Chief Innovation Officer
Blended Technologies
(www.blendedtechnologies.com)
#This is the code that's causing my problem:
#----------------------------------------------------------------------
import random
import sys
class Test_Class:
pass
class Node:
def __init__(self):
self.arg0=0
self.arg1=0
self.arg2=0
self.arg3=0
def snip(node):
prob_of_returning_this_node=.4
if random.random()<=prob_of_returning_this_node:
return node
else:
if hasattr(node,'__dict__') and len(node.__dict__)>0:
return snip(random.choice(node.__dict__.values()))
else:
return node
def replace_within_node(node,oldnode,newnode):
if node is oldnode:
return newnode
else:
if hasattr(node,'__dict__'):
for varname,value in node.__dict__.items():
node.__dict__[varname]=replace_within_node(value,oldnode,newnode)
return node
def generate_random_program(currdepth,mindepth=2,maxdepth=4):
node=Node()
if currdepth==maxdepth:
return node
else:
node=Node()
for varname,value in node.__dict__.items():
node.__dict__[varname]=generate_random_program(currdepth+1,mindepth,maxdepth)
return node
def breed(father,mother):
#want to take subtree from each input parameter and swap them.
snip_from_mother=snip(mother.program)
snip_from_father=snip(father.program)
program_for_father=replace_within_node(father.program,snip_from_father,snip_from_mother)
program_for_mother=replace_within_node(mother.program,snip_from_mother,snip_from_father)
return program_for_father,program_for_mother
if __name__=='__main__':
dragons=[Test_Class() for i in range(10)]
for dragon in dragons:
dragon.program=generate_random_program(0)
for i in range(100):
breed(dragons[0],dragons[1])
--
http://mail.python.org/mailman/listinfo/python-list
