When I’m executing a Python script. The following screen is what shows the ‘top’ command:

Tell me if I’m wrong or not: The screen shows that the Python script execution is taking one entire Core (%CPU: 100%), and the rest cores are using for others executions (actually sleepting)?
I’m using a Macbook Pro 10.6 with Intel Core i5.
Thnks in advance
Your Python script is a single process and so can only use one core.
You have to specifically code it to use multiple cores using something like parallel python