On 30Apr2009 10:57, Ben Finney <ben+python@benfinney.id.au> wrote: | Cameron Simpson <cs@zip.com.au> writes: | > On 29Apr2009 20:47, Tarek Ziad? <ziade.tarek@gmail.com> wrote: | > | def iterable(ob): | > | try: | > | iter(ob) | > | except TypeError: | > | return False | > | return True | > | > This is actually a bad way of doing it. Suppose using the iterator has | > side effects? | | If getting an iterator of an object has side effects, I'd say that | object's implementation is buggy. | | > For example, "ob" might be a store-of-recent-messages, which empties | > after they have been collected. Or a file() attached to a pipe. | | Neither of which should lose any items merely by getting an iterable. | | The only thing that should cause the iterable to “lose” items is | calling its ‘next’ method, which never happens with Tarek's code above. Oh. Sorry, my bad. You're absolutely right. I was confusing getting the iterator with using it. Thanks! -- Cameron Simpson <cs@zip.com.au> DoD#743 http://www.cskk.ezoshosting.com/cs/ ...if you don't get the finger several times a day [while commuting in Boston], you're not driving correctly. - Mark Parrenteau, DJ, WBCN Boston