Recursive calls and stack

[Szabolcs Nagy]

jm.suresh at no.spam.gmail.com wrote:
> Hi,
>  I have a program which literately finds the object that overlapping a
> point. The horizontal and vertical search are called recursively from
> inside each other.
> ...

in case you ever need deeply nested recursion:
one solution is to use the already mentioned sys.setrecursionlimit(n)
another is to use your own stack

dummy example:

def fact_recursive(n):
    if n>0:
        return fact_recursive(n-1)*n
    else:
        return 1

def fact_iterative(n):
    stack = []
    while n > 0:
        stack.append(n)
        n -= 1
    ret = 1
    while stack:
        ret *= stack.pop()
    return ret

actually you can always rewrite recursion with a stack and iterations

note that if you use version >= 2.4, then collections.deque is faster
for stack (and especially for queue) data structure than list.