while > for > foreach - increasingly higher level abstractions.
article stops at iteration (foreach) but misses an even higher level abstraction: filter, map, reduce. each of these can be implemented on top of foreach, and i haven't yet seen a loop that can't be decomposed into a combination of map, filter, reduce. also note that filter/map/reduce are expressions, not statements, so they are more "mathy" and thus easier to reason about.
its interesting that these are not necessarily idiomatic python despite being a slightly higher level abstraction. note they are idiomatic in all "real" functional languages, which python is decidedly not. also list comprehensions are faster than map/filter in python. (this is probably python's fault and is really dumb because you could just implement map/filter as a list comprehension. some people have criticized Guido for some of his design choices[1].)
article stops at iteration (foreach) but misses an even higher level abstraction: filter, map, reduce. each of these can be implemented on top of foreach, and i haven't yet seen a loop that can't be decomposed into a combination of map, filter, reduce. also note that filter/map/reduce are expressions, not statements, so they are more "mathy" and thus easier to reason about.
its interesting that these are not necessarily idiomatic python despite being a slightly higher level abstraction. note they are idiomatic in all "real" functional languages, which python is decidedly not. also list comprehensions are faster than map/filter in python. (this is probably python's fault and is really dumb because you could just implement map/filter as a list comprehension. some people have criticized Guido for some of his design choices[1].)
[1] http://www.quora.com/What-are-the-main-weaknesses-of-Python-...
also on topic: http://docs.python.org/library/itertools.html