Kent Johnson wrote: > Bob Gailer wrote: >> Asrarahmed Kadri wrote: >>> >>> What are generators and iterators...??And why are they are needed..?? >>> >>> I can do my stuff with a 'for' or a 'while' loop.. so why do I need an >>> ITERATOR..? >> iterators & generators do not replace while or for loops! > > No, actually iterators and generators are the foundation of for loops. > Whenever you write a for loop, Python creates an iterator to return the > values that are assigned to the loop variables. > > Writing your own iterator is a way to make a new kind of thing that can > be iterated in a for loop. Generators are a convenient way to make > iterators. They can be used to encapsulate loop logic. For some examples > see these recent threads: > http://thread.gmane.org/gmane.comp.python.tutor/36068/focus=36069 > http://article.gmane.org/gmane.comp.python.tutor/36105/match=generator
Here is another good article about what happens behind the scenes of a for loop: http://online.effbot.org/2006_11_01_archive.htm#for Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor