On Wed, 4 May 2011 02:56:28 -0700 (PDT), Devin Jeanpierre <jeanpierr...@gmail.com> wrote: : Eh, that example doesn't say what you think it does. It has the same : behavior in C: http://ideone.com/Fq09N . Python is pass-by-value in a : meaningful sense, it's just that by saying that we say that the values : being passed are references/pointers.
No, Python is not pass-by-value, because the pointer is abstracted away. You transmit arguments by reference only and cannot access the value of the reference. In C it is pass by value, as the pointer is explicit and do whatever you want with the pointer value. So, even though you have the same mechanism in C and Python, they do not have the same name. In the low-level C you only have pass by value, but you can use the pointer syntax to do whatever you want within pass by value. In the higher-level python, you do not have the flexibility provided by explicit pointers, so you need to explain the semantics without having a pointer concept defined a priori. : This is maybe one level of : abstraction below what's ideal, but Scheme, Java, etc. share this : terminology. (Ruby calls it pass-by-reference AFAIK. Whatever, a rose : by any other name...) Now, this is confusing, because the terminology is not universal and hardly intuitive. What is called transmission by reference in a Simula context (Bjørn Kirkerud's textbook on OO Programming with Simula for instance) is called object sharing in Wikipedia. What Wikipedia calls call by reference is transmission by name in the Simula context. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
