I like how python has a minimalistic and powerful syntax (-1 for the break ___ PEP).

Also, I really dislike the for/else ambiguity "butterflies".

When is the else after a loop executed?
1. When the loop isn't entered at all.
2. When the loop terminates through exhaustion of the list (does this include when the list was empty?)
3. When the loop didn't exit because of a break statement.

HINTS: The way django does it is opposite the way python does it and there may be more than one correct answer.

Any chances of cleaning this one up for python 4? I'm not sure how though I have a few ideas.

On Tue, Sep 29, 2009 at 11:47 PM, Guido van Rossum <guido@python.org> wrote:
On Tue, Sep 29, 2009 at 1:20 PM, Hatem Nassrat <hnassrat@gmail.com> wrote:
> Tue Jul 3 10:14:17 CEST 2007, Guido van Rossum wrote:
>> On 6/30/07, Matt Chisholm <matt-python at theory.org> wrote:
>> > I've created and submitted a new PEP proposing support for labels in
>> > Python's break and continue statements.  Georg Brandl has graciously
>> > added it to the PEP list as PEP 3136:
>> >
>> > http://www.python.org/dev/peps/pep-3136/
>>
>> I think this is a good summary of various proposals that have been
>> floated in the past, plus some new ones. As a PEP, it falls short
>> because it doesn't pick a solution but merely offers a large menu of
>> possible options. Also, there is nothing about implementation yet.
>>
>> However, I'm rejecting it on the basis that code so complicated to
>> require this feature is very rare. In most cases there are existing
>> work-arounds that produce clean code, for example using 'return'.
>
> I agree that this feature will only serve as a quick hack and in many
> cases it would be misused and ugly code will be the result. However,
> it seems that there are some shortcuts that have sneaked into python
> (I am a fairly new Python programmer, only since late 2.4, so don't
> shoot me). The specific one of which I speak about is:
>
> while_stmt ::=  "while" expression ":" suite
>                ["else" ":" suite]
>
> for_stmt ::=  "for" target_list "in" expression_list ":" suite
>              ["else" ":" suite]
>
> try1_stmt ::=  "try" ":" suite
>               ("except" [expression ["as" target]] ":" suite)+
>               ["else" ":" suite]
>               ["finally" ":" suite]
>
> All these else's seem like shortcuts to me. I did find a use for them,
> once I found out they existed, but I get butterflies whenever I do.

In English, butterflies are usually a good thing (they mean you'e in love).

These else clauses (assuming you're talking about that) have been in
the language pretty much forever. The combined except/finally clause
is newer, it was added because Java allows it and it was actually a
pretty common usage.

--
--Guido van Rossum (home page: http://www.python.org/~guido/)