CS21 Lab 7: Top-Down Design (hangman)

You may work with one partner on this assignment. If you work with a partner, put your name and the name of your partner in the list of authors at the top of your program. Only one partner needs to run handin21 to submit the files for the group. Both partners will receive the same grade.

Run update21, if you haven't already, to create the cs21/labs/07 directory. Then cd into your cs21/labs/07 directory and create the python programs for lab 7 in this directory (handin21 looks for your lab 7 assignments in your cs21/labs/07 directory). If you just want to start with your Lab 6 solution:

$ cd ~/cs21/labs/07
$ cp ../06/guess.py hangman.py

For this assignment, you will write a program that implements the hangman game (you can use the "apples falling from the tree" alternative if you want). The focus of this assignment is for you to practice using top-down design to construct your solution incrementally. You should make use of your programs from Lab 6 in this assignment.

Hangman is a simple letter guessing game. The computer picks a word (from a file) and displays it with underscores replacing the letters. The user tries to figure out the word by guessing one letter at a time. The user loses if they guess too many incorrect letters.

Here are two examples of how your hangman program should work.

$ python hangman.py
  -------------------------------
  Welcome to  H A N G M A N  v1.0
  -------------------------------

 _____      incorrect guesses left: 6

Enter a letter: e
Sorry...no e...

 _____      incorrect guesses left: 5

Enter a letter: a
yes, there's a a in the mystery word(s)!

 _a___      incorrect guesses left: 5

Enter a letter: p
yes, there's a p in the mystery word(s)!

 _app_      incorrect guesses left: 5

Enter a letter: a
you already guessed that letter :(
Enter a letter: h
yes, there's a h in the mystery word(s)!

 happ_      incorrect guesses left: 5

Enter a letter: y
yes, there's a y in the mystery word(s)!

Correct....HAPPY

You got it with 5 guesses left! SUPER.

$ python hangman.py
  -------------------------------
  Welcome to  H A N G M A N  v1.0
  -------------------------------

 ________      incorrect guesses left: 6

Enter a letter: q
Sorry...no q...

 ________      incorrect guesses left: 5

Enter a letter: w
Sorry...no w...

 ________      incorrect guesses left: 4

Enter a letter: d
Sorry...no d...

 ________      incorrect guesses left: 3

Enter a letter: z
Sorry...no z...

 ________      incorrect guesses left: 2

Enter a letter: x
Sorry...no x...

 ________      incorrect guesses left: 1

Enter a letter: m
Sorry...no m...

You L O S E !!!
The answer was....PLATYPUS

• The program should get it's randomly-chosen word from a file of words (e.g., words.txt)
• The user should be able to enter either upper or lowercase letters
• Tell the user if they have already entered a given letter (and don't count it against them)
• Update the display after each letter guessed and tell the user how many incorrect guesses they have left

• In python you can test if a character is in a given string with something like this:

  if 'a' in mystring:
     ...
  

  Use not in to test if a character is not in a string.
• At some point in your program it might be easier to work with a list of characters, instead of a string of characters. Here's how you can convert a string to a list, and then use join to get a string again:

  >>> from string import *
  >>> word = "apple"
  >>> charList = list(word)
  >>> charList
  ['a', 'p', 'p', 'l', 'e']
  >>> rejoined = join(charList, '')
  >>> rejoined
  'apple'
  

  or, using the str class methods:

  >>> rejoined = ''.join(charList)
  >>> rejoined
  'apple'
  

Here are some fun extensions that you might want to add to your program:

• give the user a choice or word topics (harry potter, tv cartoon characters, rock bands)
• allow answers with more than one word (e.g., PERRY THE PLATYPUS)
• let the user choose the difficulty of the game (easy, medium, hard)
• allow user to quit or solve the puzzle at any point in the game

Once you are satisfied with your program, hand it in by typing handin21 at the unix prompt. If you work with a partner on this assignment, only one of you needs to run handin21.

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