for loop

[houbahop]

thank you,
Whith python, It seems that all that I have learn in other languages is not 
directly usable :) but looks like python is more efficient.
dominique.

<loritsch at gmail.com> a écrit dans le message de news: 
1102879412.398726.191760 at c13g2000cwb.googlegroups.com...
> houbahop wrote:
>> Hello,
>> I have seen a lot of way to use the for statement, but I still don't
> know
>> how to do:
>>
>> for i=morethanzero to n
>> or
>> for i= 5 to len(var)
>>
>> of course I kno wthat I can use a while loop to achieve that but if
> this is
>> possible whith a for one, my preference goes to the for.
>>
>> regards,
>> Dominique.
>
> I think the key point that hasn't been made here is what a for
> statement is really doing in python...
>
>>From the online documentation:
>
> "The for statement is used to iterate over the elements of a sequence
> (such as a string, tuple or list) or other iterable object"
>
> Neither of the statements:
>> for i=morethanzero to n
>> for i= 5 to len(var)
> create a sequence or iterable object, and that is why they don't work.
>
> That is why previous posts in this thread have suggested using range(),
> xrange(), etc.  Because they create a sequence or iterable object.
> When first using python, I recall that this distinction was not clear
> to me, as I was used  to a more traditional for statement (as in
> C/C++):
>
> for ( initialise ; test ; update )
>
> Essentially, python's for statement is more like a foreach statement in
> many other languages (Perl, C#, etc).  These statements essentially
> reduce the traditional form above to what many consider a more readable
> form:
>
> foreach item in collection:
>
> In order to transform the tradition for statement into this more
> readable form, each language requires that their collections being
> iterated over satisfy a precondition defined by the language (in python
> this precondition is that the collection is iterable).
>
> While this restriction may seem a little strange to people who are used
> to the more traditional for statement form, the result of this approach
> is often a more readable and clear statement.
> Regards,
>
> Michael Loritsch
>