On Sep 21, 5:37 pm, Cristian <[EMAIL PROTECTED]> wrote: > A friend of mine is an engineer and he's been needing to do more and > more programming as he goes on with is career. I convinced him to > learn Python instead of Perl and he's really started to like it. He > usually comes to me when he can't accomplish a task with his current > knowledge and I introduce him to a new feature in Python. FYIW, he > thought List Comprehensions were freakin' awesome. He's started > writing his own personal scripts for tasks like web scraping. So, from > personal experience, Python truly is a great first language to learn. > > Although his learning experience has gone mostly smoothly, he's hit a > lot of speed bumps with functions. Specifically, he's having trouble > thinking of functions as first order data (don't worry, I haven't > confused him with such terminology yet). He had a little trouble > understanding that you can pass functions as arguments to other > functions (e.g., passing a key to the list.sort method). He also had a > little trouble grasping functions within other functions. Last but not > least, he had trouble grasping methods in class declarations, > especially the required self as the first argument (I'm sure he wasn't > the first). > > Now, my friend's a smart guy so I know it isn't any lack of brain > cells on his part. I still remember many students in my CS classes > having trouble grasping the very same concept. And, after we finally > get a hold of first order functions, we appreciate its incorporation > into languages. It would be a shame if my friend just learns the > motions and never incorporates first order functions into his > programs. I began to wonder if there was anything Python could do to > help newcomers grasp the power of first order functions or, as > Pythonistas put it, everything is an object. > > To me, the biggest setback for new programmers is the different syntax > Python has for creating functions. Instead of the common (and easy to > grasp) syntax of foo = bar Python has the def foo(): syntax. So, when > a new programmer is first introduced to functions they are immediately > confronted with the notion that functions are "different". After all, > they have their own special syntax. This seems to only further the > separation newbies make between "data" and "functions" or "stuff" and > "actions". Now, the vast majority of us learned this dichotomy when we > first began to program, so we are ingrained to assume and even expect > a different syntax for function declaration, but in a program like > Python there doesn't seem to be any other reason to have it. > Furthermore, I think it actually inhibits the learning of the > uninitiated. We can, of course, keep the current syntax as sugar. > > To someone who's learning to program wouldn't a syntax like the > further give them all they need and also reinforces the idea that > functions are data just like everything else? > > my_function = function(foo, bar): pass > an_instance_method = function(self, foo): pass > a_method_declaration = method(self, foo): pass > > The last one is mostly my pet peeve of having Python "magically" > create methods out of (what is essentially) a function declaration. > When I first learned it, it felt wrong but you had to press through it > because there was really no other way of declaring methods. > > What do you think? Have you hit this roadblock when helping others > learn Python? Does the current syntax make you feel that functions are > still treated as second class (get it?) citizens?
There are already anonymous functions in Python. lambda x, y, z: x + y + z is the same as: def _(x, y, z): return x + y + z As for the method stuff, check out staticmethod(). If you assign staticmethod(<function here>) to an object, it will be treated as a normal function and not as a "method." I have my own personal opinions about how methods should be in Python, but, whatever. It's weird to deal with stuff like this: x.y = re.match # Assign a function to an attribute of a class, but it doesn't work because you can't assign anything but methods! x.y = staticmethod(re.match) # Ugly -- http://mail.python.org/mailman/listinfo/python-list
