On Sun, Sep 20, 2009 at 1:27 PM, kevin parks <k...@mac.com> wrote: > > On Sep 21, 2009, at 1:32 AM, Alan Gauld wrote: > >> kevin parks wrote: >> >>> called, and what it is an example of. I guess there are generators and >>> iterators now and it seems this might be an example of one of those new >> >> This is a generator expression. > > That's unfortunate news for me.
Why? > So... then to call (by call i mean use/execute/doit) i would do, what? > foo.next() Are you asking how to use a generator function? There is a simple example on the recipe page (sorry, I omitted the link earlier) http://code.activestate.com/recipes/528936/ >>> list(roundrobin('abc', [], range(4), (True,False))) ['a', 0, True, 'b', 1, False, 'c', 2, 3] Calling a generator function gives you something that can be iterated. You can create a list out of it (by passing it to the list() function) or you can iterate the items in it directly with a for loop. Using the example above, you could say for item in roundrobin('abc', [], range(4), (True,False)): print item > I kinda understand conceptually what iterators and generators do and why > they are "a honking good idea" (why create 100 of x when we just want the > 100th, etc.) what i don't get is the syntax and how they are used in real > life. How generator and iterators behave in the wild. It's really not that bad. They are just a generalization of what you have already been doing with lists. > Even the Lutz is too > terse and generally poor on these two complex and relatively new constructs. > They are a dark and obscure magic. No, really they are not difficult. Read my essay and ask questions if you don't understand. Kent _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
