Python : Roll the Dice Multiple Times

We would like to expand the code from the previous exercise to allow multiple rolls of the dice without having to re-run the program each time. This exercise introduces the following concepts:

• Whitespace
• String Manipulation
• Functions
• While Loops
• If Control Statements

To your existing ‘Roll the Dice’ code add the lines below:

import random

run_prog = True

def roll_the_dice():
  random_number = random.randint(1,6)
  print("The dice rolled: " + str(random_number))

while run_prog == True:
  user_choice = input("Press [Enter] to roll the dice or [x] to exit ").lower()
  if user_choice == "x":
    run_prog = False
  else:
    roll_the_dice()

Think About the Code

• Line 3 creates a variable named ‘run_prog’ and we use this later on line 9 to determine if the dice should be rolled again or if the program should exit
• Lines 5-7 we create our own function using the ‘def’ to define the name of the function as ‘roll_the_dice’. This means that each time we use ‘roll_the_dice()’ the lines of code inside our function are run. Notice that any lines indented to the right form part of the function.
• On line 9 we use another special command ‘while’ . This allows us to ‘loop’ indefinitely. Continuously running the code underneath the ‘while’ while a particular condition remains true. For our while loop we will keep running until something changes run_prog from true to false.
• On line 10 we ask the user for some input. We also use string manipulation convert the input to lower case – just in case the user puts a capital X in. Computers view ‘x’ and ‘X’ as two different characters.
• On line 11 we make a decision using an IF statement. We say that ‘if‘ the user supplied an ‘x’ into the ‘user_choice’ variable ‘Then‘ run the code below i.e. set ‘run_prog’ to be false ( this has the effect of stopping the ‘while’ loop created on line 9).
  ‘If‘ the user_choice variable is not an ‘x’ then the ‘else‘ code will be run i.e. we run the function defined earlier and named ‘roll_the_dice’.
• Notice that the code inside the if statement is indented to the right to show the lines that belong to the ‘if’ and the lines that belong to the ‘else’

What Next

• You could expand this game to create games like ‘frustration’ or ‘snakes and ladders’
• Next Challenge: Create a python program that will generate usernames by random combining adjectives and nouns (exercise here)