Hi,
I'm having a rather obscure problem with my custom __reduce__ function. I can't
use
__getstate__ to customize the pickling of my class because I want to change the
actual
type that is put into the pickle stream. So I started experimenting with
__reduce__, but
am running into some trouble.
I've pasted my test code below. It works fine if 'substitute' is True, but as
soon as it
is set to False, it is supposed to call the original __reduce__ method of the
base
class. However, that seems to crash because of infinite recursion on Jython and
IronPython and I don't know why. It works fine in CPython and Pypy.
I wonder if my understanding of __reduce__ is wrong, or that I've hit a bug in
IronPython and Jython? Do I need to do something with __reduce_ex__ as well?
Any help is very much appreciated.
Irmen de Jong
# ironpython / jython __reduce__ recursion problem test program
import pickle
class Substitute(object):
def __init__(self, name):
self.name=name
def getname(self):
return self.name
class TestClass(object):
def __init__(self, name):
self.name=name
self.substitute=True
def getname(self):
return self.name
def __reduce__(self):
if self.substitute:
return Substitute, ("SUBSTITUTED:"+self.name,)
else:
# call the original __reduce__ from the base class
return super(TestClass, self).__reduce__() # crashes on
ironpython/jython
obj=TestClass("janet")
s=pickle.dumps(obj)
d=pickle.loads(s)
print(d)
print(d.getname())
# now disable the substitution and try again
obj.substitute=False
s=pickle.dumps(obj)
d=pickle.loads(s)
print(d)
print(d.getname())
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