---------- Forwarded message ----------
Date: Wed, 24 Aug 2005 11:24:44 -0700
From: [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
To: Danny Yoo <[EMAIL PROTECTED]>
Subject: Re: [Tutor] try except continue
hi Danny, I finally had a chance to review your explanation of
continue you wrote a while back, and I think I understand it. You say
the program will filter empty lines from standard input. I expected
the behavior to be such that, upon running the program, and typing:
hello
Danny
and pressing ctrl-d, I would get:
hello
Danny
Instead, I got the former output, which surprised me. Why doesn't
your program work as I expected ? I then wondered what your program
would do if I slightly modified it. *grin*
import sys
for line in sys.stdin:
print line
This time, running the same former test, I got the following output:
hello
Danny
As you can see, there are three empty lines now, not just one ! Where
did the extra empty lines come from ?
On 7/28/05, Danny Yoo <[EMAIL PROTECTED]> wrote:
>
>
> Hi Tpc,
>
> I should have written an example of 'continue' usage to make things more
> explicit. Here is a simple example:
>
> ###
> """Filters empty lines out of standard input."""
> import sys
> for line in sys.stdin:
> if not line.strip():
> continue
> print line
> ######
>
> This is a small program that filters out empty lines from standard input.
> The 'continue' statement causes us to immediately jump back to the
> beginning of the loop and to keep going.
>
>
>
>
> In Python, continue is intrinstically tied with Python's looping
> operations (while/for).
>
> http://www.python.org/doc/ref/continue.html
>
> It has very little to do with exception handling, except where the
> footnotes mentions certain artificial limitations in using it within an
> exception-handling block.
>
>
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