Jussi Piitulainen <[email protected]>: > In alleged contrast, the observable behaviour of languages that "have > variables" is the same. This is not considered confusing by the people > who insist that there are no variables in Python.
But of course there are variables in Python: By “frozen” we mean that all local state is retained, including the current bindings of local variables, [...] (<URL: http://docs.python.org/3.2/reference/simple_stmts.html #the-yield-statement>) The public names defined by a module are determined by checking the module’s namespace for a variable named __all__ (<URL: http://docs.python.org/3.2/reference/simple_stmts.html #the-import-statement>) It would be impossible to assign to a global variable without global (<URL: http://docs.python.org/3.2/reference/simple_stmts.html #the-global-statement>) etc etc. However, your point about "observable behavior" is key, and Python users of all people should get the principle (as it is related to duck typing). > Python indeed does not pass variables (and this is a relevant), but > neither do the other languages that "have variables". Maybe the idea comes from the fact that you can't easily pass a variable to a function for modification. Consider this C function: void make_printable(const char **ref) { if (!*ref) *ref = "<NULL>"; } which allows: make_printable(&x); make_printable(&s->name); make_printable(&a[i]); Marko -- https://mail.python.org/mailman/listinfo/python-list
