On Mon, Nov 14, 2016 at 3:54 PM, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: >> Any particular reason to write it that way, rather than: >> >> def isiterable(obj): >> try: >> iter(obj) >> return True >> except TypeError: >> return False > > > class BadIterable: > def __iter__(self): > self.launch_missiles() > return self > > > In general, merely testing whether something is a certain kind of thing > shouldn't actually run that thing's code.
True, but ISTR there being a possibility that __iter__ could raise to indicate that this isn't actually iterable. Maybe I'm recalling wrong. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
