Run update21, if you haven't already, to create the cs21/labs/06 directory. Then cd into your cs21/labs/06 directory and create the python program for lab 6 in this directory (handin21 looks for your lab 6 assignments in your cs21/labs/06 directory):

$ update21
$ cd ~/cs21/labs/06
$ pwd
  /home/your_user_name/cs21/labs/06

Your programs are graded on both correctness and style. Please review the comments regarding programming style on the main page.

Write a program called slotmachine.py that allows the user to play a simplified slot machine. In this program all users start with $10 and each play costs $2. The user may play the machine as long as they want, if they have enough money.

Our simplified slot machine will have three reels, where each reel has four possible symbols: heart, bar, lemon, star. For a single play, the winnings are as follows:

• all three reels match:
  • if they are all hearts, the user wins $50
  • otherwise, the user wins $5
• two of the three reels match (any two), the user wins $2
• none of the reels match, the user wins $0

Therefore, since it costs $2 to play, the user will only gain money if all three reels match.

Here is a sample run of the slotmachine program:

$ python slotmachine.py

Welcome to SlotMachine v0.1
---------------------------
It costs $2 to play.
If all 3 reels match, you get $5.
If all 3 reels are HEARTS, you get $50!
If 2 reels match, you get $2. 
Otherwise...you get nothing!

------------------------------

You have $10 left in your wallet
play the slots? [quit or Play]: play
*******************************
*** lemon -- heart -- lemon ***
*******************************
two symbols match...you win $2
------------------------------

You have $10 left in your wallet
play the slots? [quit or Play]: zebra
play the slots? [quit or Play]: play
*******************************
*** lemon --  bar  -- heart ***
*******************************
L-O-S-E-R
------------------------------

You have $8 left in your wallet
play the slots? [quit or Play]: play
*******************************
*** heart -- heart -- heart ***
*******************************
winner! ($50)
------------------------------

You have $56 left in your wallet
play the slots? [quit or Play]: quit

Thanks for playing!

• Your program should have at least 3 functions.
• One of those functions should get and validate the user's input. If they type quit or play, accept the input and return the user's choice to main(). If they type anything else (like "zebra"), ask again for their choice (see the above example).
• Additionally, since we want to make it easy for users to keep playing, write your function to accept the empty string (user just hits Enter key) as the default option to "play" (see example below).
• Furthermore, entering "Quit", "quit", " quit ", or "Play", "PLAY", etc should all work.
• Another function should spin the 3 reels, display the result, and return the winnings back to main()
• Finally, your main() function should start the user with $10 and keep playing until the user enters "quit" or runs out of money (doesn't have enough to play).

$ python slotmachine.py

Welcome to SlotMachine v0.1
---------------------------
It costs $2 to play.
If all 3 reels match, you get $5.
If all 3 reels are HEARTS, you get $50!
If 2 reels match, you get $2. 
Otherwise...you get nothing!

------------------------------

You have $10 left in your wallet
play the slots? [quit or Play]:       <-- user hit Enter key here
**********************************
*** orange --  heart --  heart ***
**********************************
two symbols match...you win $2
------------------------------

You have $10 left in your wallet
play the slots? [quit or Play]: 
**********************************
***   star --  heart --  heart ***
**********************************
two symbols match...you win $2
------------------------------

You have $10 left in your wallet
play the slots? [quit or Play]: 
**********************************
***  lemon -- orange --    bar ***
**********************************
L-O-S-E-R
------------------------------

You have $8 left in your wallet
play the slots? [quit or Play]: quit

Thanks for playing!

If you want an extra challenge, just for fun (no points), try these:

• use the Zelle graphics library to display the slot machine reels for each turn
• our slot machine is not very realistic; make your slot machine more realistic by changing the odds of winning and the pay table
• using a more realistic slot machine, simulate how long it would take to go broke if you just kept spinning

Once you are satisfied with your programs, hand them in by typing handin21 at the Linux prompt.

You may run handin21 as many times as you like, and only the most recent submission will be recorded. This is useful if you realize, after handing in some programs, that you'd like to make a few more changes to them.