My favorite part of python is regular expressios: Here is a nice example you could use:

Like creating a program that searches a database:

import re

a = re.compile("(^(?:0?[1-9]:[0-5]|1"
...

I will suggest declare a variable that controls your thread, when this variable has certain value you can send the thread to sleep for x seconds, and then wake it up again. What I mean with this is...

I need to do a non-recursive function for count the leafs in a tree. I have the recursive algorithm, Can someone help me to figure this out!!

count leafs

int count_Lnodes(root, int cnt)
{
...