When reading Yanaconda source code, there is one single golden rule:

EVERYTHING ENCLOSED IN PARENTHESES ( ) IS EVALUATED AND REPLACED BY THE RESULT

Example:

Name = 'Yami'
Print 'Hi I am (Name)!'

Hi I am Yami!

And a more extreme example:

Name = 'Yami'
Function = 'Print'
Argument = 'Hi I am (Name)!'
(Function) (Argument)

Hi I am Yami!

In short, the pair of opening and closing parentheses is called an 'explicit evaluator', because it explicitly forces the evaluation of an expression at any location in the source code. The entire expression including the parentheses is replaced by the value of the expression.