enumerate is very useful and now "progresserate"
francisgavila at yahoo.com
Thu Nov 20 00:41:26 CET 2003
Brian Kelley wrote in message
<3fbbbffd$0$577$b45e6eb0 at senator-bedfellow.mit.edu>...
>It also inspired me to write "progresserate" which returns the percent
>completed of the list and the current value.
>This is useful for updating progress bars and the like. I use it all
>the time, it sure saves code duplication.
>Is this idea something that is useful enough for inclusion in the
>standard library? (Not this code as-is, I don't show error checking for
It's very neat (I always seem to want to turn every problem into a generator
problem :). But actually, in this case (unless that error checking code you
mention forbids it), you don't need a class. The only methods you define
are for the generator protocol, and none of them have arguments. So a
generator function is enough (and undoubtably faster):
size = float(len(seq))
iterator = iter(seq)
i = 0
#what did self.last do?
while True: #StopIteration from iterator will propagate.
value = iterator.next()
i += 1
percent = int(i/size * 100)
yield percent, value
>One stylistic question, I tend to use
>def __iter__(self): return self
>when writing these styles of iterators. It kind of bugs me, is there a
Could you be more specific? What bugs you about it?
If it's the 'self' you mean, then know that that corresponds exactly to the
behavior of iterators currently: if you request an iterator from an
iterator, it returns itself (what else would it return?). If you want a
*copy* of an iterator, you have to wait until PEP 323.
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