why does this fail on python 2.2?

[John Hunter]

I'm trying to understand why some code from a module I'm using is
failing on 2.3 but working on 2.3. Here is the minimal example that
replicates the problem

class Results(object):
__slots__ = ( "__doinit" )
def __new__(cls):
retobj = object.__new__(cls)
retobj.__doinit = True
return retobj

x = Results()

On python2.2, this fails with

mother:~/tmp> python2.2 test.py
Traceback (most recent call last):
File "test.py", line 8, in ?
x = Results()
File "test.py", line 5, in __new__
retobj.__doinit = True
AttributeError: 'Results' object has no attribute '_Results__doinit'

 

[John Hunter]

Larry> Because __slots__ and __new__ were added in 2.3. Larry

I don't think so

http://python.org/2.2.3/descrintro.html

 

[Larry Bates]

Because __slots__ and __new__ were added in 2.3.

Larry Bates
Syscon, Inc.

 

[Rob Williscroft]

John Hunter wrote in (e-mail address removed) in comp.lang.python:

class Results(object):
__slots__ = ( "__doinit" )
def __new__(cls):

AttributeError: 'Results' object has no attribute '_Results__doinit'

Its in the Traceback:

__slots__ = [ '_Results__doinit' ]

Rob.