> To illustrate the neither-fish-nor-fowl nature of Python calls: > > mwilson@tecumseth:~$ python > Python 2.6.5 (r265:79063, Apr 16 2010, 13:09:56) > [GCC 4.4.3] on linux2 > Type "help", "copyright", "credits" or "license" for more information.>>> def > identify_call (a_list): > > ... a_list[0] = "If you can see this, you don't have call-by-value" > ... a_list = ["If you can see this, you have call-by-reference"] > ...>>> my_list = [None] > >>> identify_call (my_list) > >>> my_list > > ["If you can see this, you don't have call-by-value"] > > so it's neither call-by-value nor call-by-reference as (e.g.) C or PL/I > programming would have it (don't know about Simula, so I am off topic, > actually.) It's not so wrong to think of Python's parameter handling as > ordinary assignments from outer namespaces to an inner namespace. > > Mel.
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. 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...) Devin Jeanpierre -- http://mail.python.org/mailman/listinfo/python-list
