if number = print('even number'else run if test is true indentation upper middle print('that was fun!' the test line is immediately followed by the block of code that is run if the test evaluates as true because it is block of code it is indented by four spaces to mark it as block this example has single linebut the block can be as long as you want this block is sometimes called the "then-blockbecause "if the test is true then run this block