Please comment on Draft PEP for Enhanced Generators
mcherm at destiny.com
Wed Jan 30 17:36:10 CET 2002
One minor detail:
> def ints(cnt=0, limit=None):
> 'Generate an integer sequence starting a zero or cnt upto limit or infinity'
> while not limit or cnt < limit:
> yield cnt
> cnt += 1
Calling ints(0,0) should probably not yield the sequence:
0, 1, 2, 3, ...
I would instead expect an empty sequence! I would suggest this tiny
def ints(cnt=0, limit=None):
"""Generate an integer sequence starting a zero or cnt upto limit
while limit is None or cnt < limit:
cnt += 1
As for my overall thoughts:
* The new built-ins are all good ideas. Do them immediately. The only
unnecessary bit (that other still-under-consideration PEPs contain
other ways of achieving ints()) is already mentioned in your PEP.
* Generator comprehensions seem to be potentially useful, though I'm
not really sure. The syntax is nice, the only issue is whether
their utility is sufficient to meet the bar to be worth extending
the language. I'm on the fence.
* Two-way generator parameter passing seems awefully bold. To my
mind, one of the great things about generators is that they meet
the (very simple) definition of an iterator. With this, they no
longer do. I like lazy consumers -- really I do -- but I'd rather
be conservative about putting something like this in the language.
And hey... great work in writing these up!
-- Michael Chermside
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