On Tuesday, May 12, 2015 at 8:15:07 PM UTC-5, Steven D'Aprano wrote: > On Wed, 13 May 2015 02:05 am, Chris Angelico wrote: > > > So if you're writing a library function, it probably shouldn't use > > print()... but your application is most welcome to. You usually know > > which one you're writing at any given time. > > You might be, but beginners are not. > > I'm not sure I accept Rustom's fix for the problem (I think that his cure is > worse than the disease), but it is *hard* to get some beginners to use > return instead of print: > > def add_twice(x, y): > """Add twice y to x.""" > print x + 2*y > > > sort of thing. > > Personally, I think that banning print is only useful if you wish to > encourage cargo-cult programming: > > "Don't use print!" > "Why not?" > "My CS lecture said not to use it! I dunno, maybe it has a virus or > something."
No, no, no. There's a very simple reason that you don't put extraneous I/O into your functions: you want your functions to be as general as possible for the given focus for re-usability. Otherwise, why write as a separate function? It's called separability of domains. See Hacking with the Tao: http://wiki.hackerspaces.org/Hacking_with_the_Tao. Mark -- https://mail.python.org/mailman/listinfo/python-list
