PEP-315 ("do" loop)
paul at prescod.net
Tue Feb 17 16:50:53 CET 2004
Wayne Folta wrote:
> ... How about, instead, creating an "until" loop:
> until line == "\n":
> line = sys.stdin.readline()
> Would be defined to work exactly like a while loop except the test is
> not evaluated the first time through the loop. Wouldn't this be akin to
> checking at the end of the loop, while maintaining a more while-ish syntax?
is maintaining a while-ish syntax the right thing to do? After all, the
"until" code is conceptually evaluated at the bottom, not the top of the
loop. I would naively think that "until" is just a "while" that inverts
its condition. i.e.
until x <==> while not x
Nothing about the word "until" implies to me that it delays the loop
test on the first go-round. PEP 315's syntax seems more clear to me.
More information about the Python-list