Flow of control

if/elif/else statements are used to make complex decisions. It's perhaps the most used statement to control program flow.

Let's input a choice, then see the visual result in CodeCraft world:

Example: choice

Let's build 5 white columns, then depending on your choice, one of them will be highlighted with a specific color:

# 5 white columns
pool = [3, 2, 4, 8, 1]
for i in range(5):
    column(i, -20, pool[i], 'quartz')

Run the program to see the 5 white columns, then add the following code:

choice = int(input('Enter your choice of number from 1 to 5: '))

if choice == 1:
  print('1, blue')
  column((choice-1), -20, pool[choice-1], 'linen_blue')
elif choice == 2:
  print('2, red')
  column(choice-1, -20, pool[choice-1], 'linen_red')
elif choice == 3:
  print('3, yellow')
  column(choice-1, -20, pool[choice-1], 'linen_yellow')
elif choice == 4:
  print('4, pink')
  column(choice-1, -20, pool[choice-1], 'linen_pink')
elif choice == 5:
  print('5, purple')
  column(choice-1, -20, pool[choice-1], 'linen_purple')

else:
  print( 'You entered an invalid choice. No column is chosen')

Run the whole program a few times. Each time enter a different number to see the chosen column highlighted with a color.

Such as: 4, pink

Extra Practice

Let's make a square that is a solid color but has a different color on its diagonals. This can be done with an if statement inside nested for loops:

# Square_X
for i in range(-5, 6):
    for j in range(-5, 6):
        if abs(i) == abs(j):
            m = 'box_black'
        else:
            m = 'box_blue'

        block(i, 9+j, -10, m)