On 5/20/2016 8:59 AM, Zachary Ware wrote:
On Fri, May 20, 2016 at 3:09 AM, Erik <pyt...@lucidity.plus.com> wrote:
On 20/05/16 00:51, Gregory Ewing wrote:
It's not so bad with "else" because you need to look back
to find out what condition the "else" refers to anyway.
With my tongue only slightly in my cheek, if it was desirable to
"fix"/clarify this syntax then I would suggest adding some optional
(existing) trailing keywords to 'else' in this context that spells it out:
for item in seq:
if foo(item):
break
else if not break:
nomatch()
With tongue firmly cheeked, you can always use the special `:#` operator:
for item in seq:
if foo(item):
break
else:# if no break:
nomatch()
This has the benefit that you can use whatever syntax you like after
the `:#`, and use it in any version of Python you want.
According to "Effective Python: 59 Specific Ways to Write Better Python"
by Brett Slatkin, Item 12 recommends against using the else block after
for and while loops (see page 25): "Avoid using else blocks after loops
because their behavior isn't intuitive and can be confusing."
Until I read the book, I wasn't aware of this feature (or bug). Doesn't
seem like a feature I would use since it's not commonly found in other
programming languages. As the author demonstrates in his book, I would
probably write a helper function instead.
Item 13 does recommend using the else block for try/except/else/finally
in exception handling. :)
Thank you,
Chris R.
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