On Fri, 2010-04-16 at 09:50 -0700, Dave W. wrote: > >>> old_print = __builtins__.print > >>> __builtins__.print = printhook > >>> yield > >>> __builtins__.print = old_print > > > >> I'm pretty sure this is semantically equivalent to my original > >> code, but I gave it a try anyway. > > > > Not at all. Declaring "global print" then assigning to "print" > > simply changes what the module's "print" variable refers to. Other > > modules are unaffected. "Global" variables aren't truly global; > > they are actually local to the module. You need to replace it in > > the __builtins__ because that's where everyone else gets it. > > > > > FWIW, it doesn't work, either. :-} > > > > Right. Lie answered why. I didn't pay attention and thought you > > were already using Python 3. > > Thanks, Robert and Lie for the considered and informative responses. > Getting feedback like this from people who really understand > Python's internals is invaluable. Sounds like redirecting > stdout/stderr is the way to go. (Especially given that they're not > the 'real' stdout/stderr---that was news to me!) > > [xref "Suppress output to stdout/stderr in InteractiveInterpreter"]
It's good to remember that names in python are just names. The objects that have the names "sys.stdout" and "sys.stderr" are the real deal, but when you assign a file object to them, you are not actually "redirecting" anything. You are assigning a name (sys.stdout) to a different file object. The old object still points to STDOUT, but sys.stdout no longer refers to that object as long as your assignment remains in scope. -- http://mail.python.org/mailman/listinfo/python-list
