the pygame framework often represents cartesian coordinates as tuple of two integerssuch as ( or ( the first integer is the coordinate and the second is the coordinate (cartesian coordinates are covered in more detail in of --invent your own computer games with python|at reminder about functionsmethodsconstructor functionsand functions in modules (and the difference between themfunctions and methods are almost the same thing they can both be called to execute the code in them the difference between function and method is that method will always be attached to an object usually methods change something about that particular object (you can think of the attached object as sort of permanent argument passed to the methodthis is function call of function named foo()foo(this is method call of method also named foo()which is attached to an object stored in variable named duckieduckie foo( call to function inside of module may look like method call to tell the differenceyou need to look at the first name and see if it is the name of module or the name of variable that contains an object you can tell that sys exit(is call to function inside of modulebecause at the top of the program will be an import statement like import sys constructor function is the same thing as normal function callexcept that its return value is new object just by looking at source codea function and constructor function look the same constructor functions (also called simply --constructor|or sometimes --ctor|(--see-tor||for shortare just name given to functions that return new object but usually ctors start with capital letter this is why when you write your own programsyour function names should only begin with lowercase letter for examplepygame rect(and pygame surface(are both constructor functions inside the pygame module that return new rect and surface objects (these objects are described later here' an example of function calla method calland call to function inside moduleimport whammy fizzy(email questions to the authoral@inventwithpython com