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Date: Mon, 02 Sep 2013 00:30:35 +0100
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Subject: Re: semicolon at end of python's statements
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Xref: csiph.com comp.lang.python:53439

On 01/09/2013 20:58, Antoon Pardon wrote:
> Op 31-08-13 02:09, Steven D'Aprano schreef:
>> On Fri, 30 Aug 2013 11:32:17 +0100, Fábio Santos wrote:
>>
>
>>
>> We really are spoiled for choice here. We can write any of these:
>>
>> # Option 1
>> for spam in sequence:
>>      if predicate(spam):
>>          process(spam)
>>
>
>>
>> Adding a fourth option:
>>
>> for spam in sequence if predicate(spam):
>>      process(spam)
>>
>> saves absolutely nothing except a line and an indent level, neither of
>> which are in short supply, and gains nothing in readability over Option 1.
>
> So what is the big difference between this situation and the following:
>
> | else:
> |     if condition:
> |         whatever
>
> which in python we can write:
>
> | elif condition:
> |     whatever
>
>
> So either is seems this was a design mistake or a line and an indent
> level can be important enough to allow a combination of controls.
>
'elif' is for cascading ifs:

if ...:
    ...
elif ...:
    ...
elif ...:
    ...
elif ...:
    ...
else:
    ...

Without 'elif' you would be forced to write:

if ...:
    ...
else:
     if ...:
        ...
     else:
         if ...:
            ...
         else:
             if ...:
                ...
             else:
                ...

On the other hand, for...if is much less of a problem.