Project: Hangman

Project: Hangman

• The last project puts the whole course together: a game of hangman.
• You guess a word one letter at a time. Five wrong guesses and you lose.
• You use strings, lists, in, functions, a while loop and input().

What you will build

a
_a_
z
_a_
t
_at
c
cat
You won!

Plan first

• Before you write the loop, write two small functions and test them:
• mask(word, guessed) shows the word with _ for letters not guessed yet.
• is_won(word, guessed) says whether every letter has been guessed.
• Then the game loop only has to call them.

Step 1: build a string letter by letter

• Start with an empty string "".
• Loop over the word; add the letter, or _, to the end each time.
• letter in guessed is True when the list contains that letter.

Step 2: stop as soon as you know

• Loop over the letters. If one is not in guessed, return False straight away.
• If the loop finishes, nothing was missing: return True.

Step 3: the game loop

• Keep going while there are fewer than 5 wrong guesses and the word is not won.
• Inside: read a letter, remember it, count it if it is wrong, print the mask.
• After the loop, one if decides between the winning and the losing message.

Play for real

• The computer picks a secret word from a list. Type one letter at a time.

import random

def mask(word, guessed):
    result = ""
    for letter in word:
        result = result + (letter if letter in guessed else "_")
    return result

word = random.choice(["python", "loop", "list", "print"])
guessed = []
wrong = 0
while wrong < 5 and mask(word, guessed) != word:
    letter = input("Guess a letter: ")
    guessed.append(letter)
    if letter not in word:
        wrong = wrong + 1
    print(mask(word, guessed), "   wrong:", wrong)
print("You won!" if mask(word, guessed) == word else "You lost! The word was " + word)

Now build it

• Three steps. Well done for reaching the end of the course!