remember to pass tuple of two integers to set_mode()not just two integers themselves the correct way to call the function is like thispygame display set_mode(( ) function call like pygame display set_mode( will cause an error that looks like thistypeerrorargument must be -item sequencenot int the pygame surface object (we will just call them surface objects for shortreturned is stored in variable named displaysurf pygame display set_caption('hello world!'line sets the caption text that will appear at the top of the window by calling the pygame display set_caption(function the string value 'hello world!is passed in this function call to make that text appear as the captiongame loops and game states while truemain game loop for event in pygame event get()line is while loop that has condition of simply the value true this means that it never exits due to its condition evaluating to false the only way the program execution will ever exit the loop is if break statement is executed (which moves execution to the first line after the loopor sys exit((which terminates the programif loop like this was inside functiona return statement will also move execution out of the loop (as well as the function toothe games in this book all have these while true loops in them along with comment calling it the --main game loop| game loop (also called main loopis loop where the code does three things handles events updates the game state draws the game state to the screen the game state is simply way of referring to set of values for all the variables in game program in many gamesthe game state includes the values in the variables that tracks the player' health and positionthe health and position of any enemieswhich marks have been made on boardthe scoreor whose turn it is whenever something happens like the player email questions to the authoral@inventwithpython com