[Python-ideas] Updating PEP 315: do-while loops
Eric Smith
eric at trueblade.com
Sun Apr 26 03:31:17 CEST 2009
Raymond Hettinger wrote:
> Am working on PEP 315 again, simplifying the proposal by focusing on a
> more standard do-while loop.
I posted this to python-dev before I saw your post over here. Sorry
about that.
My message was:
You might want to note in the PEP that the problem that's being solved
is known as the "loop and a half" problem, at least for your motivating
case #2.
http://www.cs.duke.edu/~ola/patterns/plopd/loops.html#loop-and-a-half
> 2) A pattern of ending a "while True:" loop with an "if not <cond>:
> break". Here's an example from random.normalvariate():
>
> while 1:
> u1 = random()
> u2 = 1.0 - random()
> z = NV_MAGICCONST*(u1-0.5)/u2
> zz = z*z/4.0
> if zz <= -_log(u2):
> break
More information about the Python-ideas
mailing list