Steve Howell showell30 at yahoo.com
Fri Jun 8 01:15:33 CEST 2007

```Programs like this were posted on this thread:

>    def fib():
>        generation, parent_rabbits, baby_rabbits = 1,
> 1, 1
>        while True:
>            yield generation, baby_rabbits
>            generation += 1
>            parent_rabbits, baby_rabbits = \
>                   baby_rabbits, parent_rabbits +
> baby_rabbits
>
>     for pair in fib():
>         if pair[0] > 100:
>             break
>         print "Generation %d has %d (baby) rabbits."
> % pair
>

One goal behind the SimplePrograms page is to give
people that are new to Python a *gentle* immersion
into Python code.  I prefer simple:

parent_rabbits, baby_rabbits = (1, 1)
while baby_rabbits < 100:
print 'This generation has %d rabbits' %
baby_rabbits
parent_rabbits, baby_rabbits = (baby_rabbits,
parent_rabbits + baby_rabbits)

Somebody commented in another reply that they'd prefer
the variable names "a" and "b," but other than that, I
think it's hard to simplify this.

The problem of counting rabbits is not sufficiently
rich to motivate a solution with generator functions,
and "yield" statements are just gonna scare people
away from the Python, unless they've had a chance to
see simpler idioms first.

I do think there's a place on the page for a good
generators example, but it needs to solve a
sufficiently complex problem that the use of
generators actually simplifies the solution.

So I'm throwing down the gauntlet--can somebody write
a short program (maybe 10 to 20 lines) where you solve
a problem more simply than a similar
non-generator-using solution would solve it?  Maybe
something like Eight Queens?

-- Steve

P.S.  FWIW the page does already include examples of
generator expressions and the itertools module, but it
does not yet show any code that actually implements a
generator.  I would greatly welcome the addition of a
good example.

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