print('can install by following the instructions at' print(' sys exit( set up the constants pause_length (!try changing this to or (!try changing this to any number between and wide_fall_chance screen_width screen_height the index of values in an (xytuple is the index of values in an (xytuple is sand chr( wall chr( set up the walls of the hourglass hourglass set(has (xytuples for where hourglass walls are (!try commenting out some hourglass add(lines to erase walls for in range( ) hourglass add(( )add walls for the top cap of the hourglass hourglass add(( )add walls for the bottom cap for in range( ) hourglass add(( )add walls for the top left straight wall hourglass add(( )add walls for the top right straight wall hourglass add(( )add walls for the bottom left hourglass add(( )add walls for the bottom right for in range( ) hourglass add(( )add the top left slanted wall hourglass add(( )add the top right slanted wall hourglass add(( )add the bottom left slanted wall hourglass add(( )add the bottom right slanted wall set up the initial sand at the top of the hourglass initial_sand set( for in range( ) for in range( ) initial_sand add((xy ) def main() bext fg('yellow' bext clear( draw the quit message bext goto( print('ctrl- to quit 'end='' display the walls of the hourglass for wall in hourglass bext goto(wall[ ]wall[ ] print(wallend='' while truemain program loop allsand list(initial_sandhourglass