Tuvas wrote: > I don't know if I can help with this much, I'm still somewhat new to > python, but it is my understanding that "simple" variable, ei, strings, > ints, etc, although they don't have such names, behave like variables, > ei, if you pass them to a function, the function will copy them into a > new spot. However, if you use lists, then it only passes a pointer, or > tuples as well. Ei, I just ran this through the python IDE. > > >>> x="Test" > >>> def modstring(var): > var="Blah" > >>> modstring(x) > >>> print x > Test > > This seems to indicate that the variable is copied, as the value didn't > change. Weither or not Python keeps the variables as pointers > internally, it doesn't really matter. Actually, all languages do such > things, except assembly. No. They are not copied, at least not at function invokation. The parameter in the functions scope got rebound(that is the term python people like to use) to a new value(or object in python term as everything in python is an object) if you use the "=" operator.
x="test" y=["test"] def mod_1(v): v="blah" def mod_2(v): v[0]="blah" mod_1(x) print x mod_1(y) print y mod_2(x) print x mod_2(y) print y You can see that neither x or y changed with mod_1, regardless whether it is mutable or not. mod_2(x) is an error as it kind of use 'v' as an object pointer and invoke some method on it(the object) which doesn't exist for x. mod_2(y) works as expected, because y in this case is sort of an object which is a container which has the "[]" method. > I just ran the test on lists and tuples, it was the same results, > nothing moved. > > Other than this, I basically see a fight on terminology, and that's > that. -- http://mail.python.org/mailman/listinfo/python-list
