Step 13: If/Elif/Else¶

Tutorial¶

Sometimes you want to create branches in your code where only one out of many possible options can occur. For example, Reeborg lives in Canada where it not only can rain or be sunny, but snow can also be falling. Let’s suppose that only one of those can happen at a time. Then, Reeborg could be faced with the following choices:

if it_rains():
    play_indoors()
elif it_snows():
    go_skiing()
else:
    go_swimming() # assuming it is warm!

Notice the use of elif (which means “else if”) for choice 2. If we took into account other possible weather phenomena, like hail, thunder, fog, drizzle, etc., we could add other choices using additional elif: ... code blocks.

Here is a graphical representation of the choices that Reeborg faces:

In an if/elif/else statement, you should see that it gives three independent choices and only one of them will be executed.

Your Turn¶

Open Step 13 on the Reeborg environment, and copy/paste the following code to begin your solution:

def jump_over_hurdle():
    # suitable definition

def run_jump_or_finish():
    if at_goal():
        done()  #tells Reeborg to stop
    elif front_is_clear():
        # something
    else:
        # something

repeat 42:
    run_jump_or_finish()

Reeborg is jumping hurdles again. This time, however, the hurdles may not all be the same distance apart. You should use a repeat loop to have Reeborg jump the hurdles, and end at the goal (12, 1). You must use an if/elif/else structure in your program.