Why is local variable access faster than class member access in Python?

Question

While trying to tackle a more complex problem, I came to compare access speed to local variable vs member variables.

Here a test program:

#!/usr/bin/         


        

Answer 1

Local names is faster because Python does some optimization that local names don't need dict access, on the other hand, instance attributes need to access the __dict__ of the object.

This is also the reason why local names are faster than global names.