Updated StackBuster so less time is wasted with building huge strings.

StackBuster.py

 def non_terminating_recursion(a_string, instance_number):
-    a_longer_string = "{} {}".format(a_string, a_string)
-    # print( "Activation instance: {:d}".format(instance_number))
+    a_longer_string = f' {a_string} '
+    print(f'Activation instance: {instance_number}')
     return non_terminating_recursion(a_longer_string, instance_number + 1)