organization in the src structure, modification of README

src/USEFUL/basic_examples/example_time.py

@@ -0,0 +1,24 @@
+#!/usr/bin/python
+
+__author__ = "bt3"
+
+''' a simple example of how to time a function '''
+
+import time
+
+def sumOfN2(n):
+    start = time.time()
+    theSum = 0
+    for i in range(1,n+1):
+        theSum = theSum + i
+    end = time.time()
+    return theSum,end-start
+
+
+
+if __name__ == '__main__':
+    n = 5
+    print("Sum is %d and required %10.7f seconds"%sumOfN2(n))
+    n = 200
+    print("Sum is %d and required %10.7f seconds"%sumOfN2(n))
+