Optimizing constants in loops

[Michael Hoffman]

The peephole optimizer now takes things like

if 0:
    do_stuff()

and optimizes them away, and optimizes away the conditional in "if 1:".

What if I had a function like this?

def func(debug=False):
     for index in xrange(1000000):
         if debug:
             print index
         do_stuff(index)

Could the "if debug" be optimized away on function invocation if debug 
is immutable and never reassigned in the function? When performance 
really matters in some inner loop, I usually move the conditional 
outside like this:

def func(debug=False):
     if debug:
         for index in xrange(1000000):
             print index
             do_stuff(index)
     else:
         for index in xrange(1000000):
             do_stuff(index)

It would be nice if this sort of thing could be done automatically, 
either by the interpreter or a function decorator.
-- 
Michael Hoffman