call-by-reference (was Re: Any other Python flaws?)

Martijn Faassen m.faassen at
Fri Jun 15 15:20:53 EDT 2001

David C. Ullrich <ullrich at> wrote:
> On 15 Jun 2001 14:08:58 GMT, jcm <grumble at> wrote:

>>Martijn Faassen <m.faassen at> wrote:
>>> I agree that nobody agrees on whatever 'call-by-reference' means, or what
>>> 'call-by-value' means. I mean, I'm here confused why you'd say C++ doesn't
>>> support call-by-value while Python apparently does. :)
>>In my experience, there's good agreement about what call-by-reference
>>means just about everywhere but in newsgroups.  Python supports only
>>call-by-value -- you can't change the value of a variable in your
>>caller's scope (globals aside).

> It's call-by-value all right. The confusion is caused
> by the fact that the values are references. But passing
> a reference "by value" is not a call by reference.

I think the confusion makes it not worth saying things like "It's simple!
Python does call-by-value only!". :) Better be more specific about the


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