Paul Moore wrote:
Hmm, it took me a while to get this, but what you're ssaying is that if you modify Guido's "what I really want" solution to use
VAR = next(it, exc)
then this builtin next makes "API v2" stuff using __next__ work while remaining backward compatible with old-style "API v1" stuff using 0-arg next() (as long as old-style stuff isn't used in a context where an exception gets passed back in).
Yes, but it could also be used (almost) anywhere an explicit obj.next() is used.
it = iter(seq)
while True: print next(it)
for loops would also change to use builtin next() rather than calling it.next() directly.
I'd suggest that the new builtin have a "magic" name (__next__ being the obvious one :-)) to make it clear that it's an internal implementation detail.
There aren't many builtins that have magic names, and I don't think this should be one of them - it has obvious uses other than as an implementation detail.
PS The first person to replace builtin __next__ in order to implement a "next hook" of some sort, gets shot :-)
Damn! There goes the use case ;)
Tim Delaney
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