Fibonacci series recursion error

Fri Apr 29 23:41:52 EDT 2011

On 04/29/2011 08:22 PM, lalit wrote:
> import os
> def fib(n):
> 	if n == 1:
> return(n)
> 	else:
> return (fib(n-1)+fib(n-2))
>> list=fib(20)
> print(list)
>> The above function return the
> return (fib(n-1)+fib(n-2))
>>> RuntimeError: maximum recursion depth exceeded in comparison
> [36355 refs]
>> can any one help

You correctly test for n==1, but what about when n==2? When the 
recursion works its way down to fib(2), you call both fib(1) and fib(0), 
but the latter starts an infinite sequence of calls to fib(-1), fib(-2) 
and so on without end.
Gary Herron