On Friday, March 14, 2014 5:11:03 AM UTC+5:30, Steven D'Aprano wrote: > On Thu, 13 Mar 2014 14:27:48 +0200, Marko Rauhamaa wrote:
> > Roy Smith : > >> Steven D'Aprano wrote: > >>> Because Python doesn't have true procedures > >> What do you mean by "true procedure"? Are you just talking about > >> subroutines that don't return any value, i.e. fortran's SUBROUTINE vs. > >> FUNCTION? > > Ah, the "no true procedure" argument: > > - No true procedure returns a value. > > - That's false. Python's procedures return None. > Are you trolling again? > I'm sure that you know quite well that Python doesn't have a procedure > type. It uses a single keyword, def, for creating both functions and > functions-that-return-None. > We should all agree that functions-that-return-None are used for the same > purpose as procedures, but they are still functions, and they have a > return result, namely None. If you don't believe me, believe Python: > py> def func(): > ... return 42 > ... > py> def proc(): > ... pass > ... > py> type(func) > py> type(proc) > py> repr(proc()) > 'None' > In languages with procedures, that last line would be an error (either at > compile-time, or run-time) since a procedure wouldn't return anything to > use as argument to repr. But I'm sure that you know that. > > - They are not true procedures. > Correct. They are functions that return None, rather than a subroutine > that doesn't have any return value at all. But I'm sure you know that. I believe that you, Marko (and I) are saying exactly the same thing: Wear language-lawyer hat: Python has no procedures -- just functions which may return None Wear vanilla programmer hat: The concept (Pascal) procedure is simulated by function-returning-None -- https://mail.python.org/mailman/listinfo/python-list
