Fibonacci series recursion error

Sat Apr 30 04:14:46 EDT 2011

Am 30.04.2011 09:43 schrieb harrismh777:
> On the other hand, I am very much interested in "yield," because of its
> obvious persistent state, On the other hand, I don't like you fib()
> function because it does not encapsulate the fib generator. I suppose
> you are considering whatever module is holding the fib() code as the
> encapsulation, but I thought the idea from the OP was to create a
> generator that could be called and return a list... this is a little goofy:
> list(islice(fib(), X))
>> when what was wanted is:
>> list = fib(X)

You can have both with the following:
def fib(max=None):
 a = b = 1
 while max is None or a <= max:
 yield a
 a, b = b, a+b
from itertools import islice
flist = list(islice(fib(), 100000))
flist2 = list(fib(100000))
or - if even the latter is unwanted -
def fibgen(max=None):
 a = b = 1
 while max is None or a <= max:
 yield a
 a, b = b, a+b
def fib(max=None, num=None):
 if num is None:
 return list(fibgen(max=max))
 else:
	from itertools import islice
	return list(islice(fib(max=max), num))
Thomas