caching attribute reference

[Skaperen]

in a class method, i need to access an instance attribute, such as self.foo and use that value many times.  is there any expected performance benefit to caching it in a local variable, such as doing foo = self.foo, and using just foo instead of self.foo for all the uses?  if i modify it i could do foo = whatever or foo += somenumber then finish with self.foo = foo.