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.
<[EMAIL PROTECTED]> a écrit dans le message de news: [EMAIL PROTECTED] > 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 > -- http://mail.python.org/mailman/listinfo/python-list
