def insertion_sort(un_list):
    for idx in range(1, len(un_list)):
        current = un_list[idx]
        position = idx

        while position > 0 and un_list[position-1] > current:
            un_list[position] = un_list[position-1]
            position = position - 1

        un_list[position] = current

if __name__ == '__main__':
    BEST_CASE = range(1000)
    WORST_CASE = BEST_CASE[::-1]

    from timeit import Timer

    best = Timer(
        'insertion_sort({})'.format(BEST_CASE),
        'from __main__ import BEST_CASE, insertion_sort').timeit(1000)

    worst = Timer(
        'insertion_sort({})'.format(WORST_CASE),
        'from __main__ import WORST_CASE, insertion_sort').timeit(1000)

    print("""Best case represented as a list that is already sorted\n
        Worst case represented as a list that is absolute reverse of sorted""")
    print('Best Case: {}'.format(best))
    print('Worst Case: {}'.format(worst))

def insertion_sort(un_list):
    for idx in range(1, len(un_list)):
        current = un_list[idx]
        position = idx

        while position > 0 and un_list[position-1] > current:
            un_list[position] = un_list[position-1]
            position = position - 1

        un_list[position] = current

if __name__ == '__main__':
    pass

--- 
+++ 
@@ -10,4 +10,20 @@
         un_list[position] = current
 
 if __name__ == '__main__':
-    pass
+    BEST_CASE = range(1000)
+    WORST_CASE = BEST_CASE[::-1]
+
+    from timeit import Timer
+
+    best = Timer(
+        'insertion_sort({})'.format(BEST_CASE),
+        'from __main__ import BEST_CASE, insertion_sort').timeit(1000)
+
+    worst = Timer(
+        'insertion_sort({})'.format(WORST_CASE),
+        'from __main__ import WORST_CASE, insertion_sort').timeit(1000)
+
+    print("""Best case represented as a list that is already sorted\n
+        Worst case represented as a list that is absolute reverse of sorted""")
+    print('Best Case: {}'.format(best))
+    print('Worst Case: {}'.format(worst))
Update module with timeit testing for best and worst case scenarios.
