Modifying Class Object

Gerard Flanagan grflanagan at
Mon Feb 8 09:02:43 CET 2010

Arnaud Delobelle wrote:
> "Alf P. Steinbach" <alfps at> writes:
>> * Chris Rebert:
>>> On Sun, Feb 7, 2010 at 5:05 PM, T <misceverything at> wrote:
>>>> Ok, just looking for a sanity check here, or maybe something I'm
>>>> missing.  I have a class Test, for example:
>>>> class Test:
>>>>    def __init__(self, param1, param2, param3):
>>>>        self.param1 = param1
>>>>        self.param2 = param2
>>>>        self.param3 = param3
>>>> Next, I have a dictionary mytest that contains instances of Test.  If
>>>> I want to modify one of the Test instances within my dictionary, I
>>>> have to rewrite the entire entry, correct (since Python passes by
>>>> value, not reference)?
>>> Incorrect; Python uses neither. See
>>> for a excellent explanation
>>> of what Python does use.
>> Hm. While most everything I've seen at has been clear and
>> to the point, that particular article reads like a ton of obfuscation.
>> Python passes pointers by value, just as e.g. Java does.
> Please! Not this again! This has been discussed to death and beyond more
> than enough times.  Go search the c.l.p archives, read it all, and I'm
> sure you won't want to add anything anymore.

+1 !!

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