The Pixelated Coder 👨💻
Link:https://beastgetssavvy13.github.io/Rock-Paper-Scissor-with-Comp/Rockpaperscissor.html
Top-Down Programming Example: Rock, Paper, Scissors Step #1: Goal and General Algorithm Idea Goal: write a game to play “rock, paper, scissors” The user chooses one of these, the computer chooses the other
If the pair is “rock, paper”, the paper wins If the pair is “scissors, paper”, the scissors wins If the pair is “scissors, rock”, the rock wins Specification: user enters selection of rock, paper, scissors Program prints computer’s selection, who wins At end, computer prints number of games human won and it won High-level design: initialize score loop ask user for choice if quit, exit loop computer selects one select winner and increment win count endloop print number of games user won, computer won, ties
Step #2: Data Representation and Program Structure Part #1: Data Represent the rock, paper, scissors using strings: “rock”, “paper”, “scissors” (sequence things) Represent commands as strings as above, plus “quit” (sequence cmdlist) Store the scores in a dictionary with keys “user”, “computer”, “tie” and integer values (initially set to 0)
Part #2: Functions
get user input – getuser() get computer choice – getcomp() determine winner – whowins() Part #3: Refine algorithm
while True:
userchoice = getuser();
if (userchoice == quit):
break
compchoice = getcomp();
winner = whowins(userchoice, compchoice)
score[winner] += 1
print You won, score[“user”], game(s), the computer won, score[“computer”], game(s)
print and you tied, score[“tie”], game(s)
Step #3: Figure out who wins Represent (object1, object2) where object1 beats object2 as list of tuples, winlist. To see if user won, see if the (user-chosen object, computer-chosen object) tuple is in that list.
This leads to [rps-prog1.py]:
def whowins(user, comp): if user == comp: win = "tie" elif (user, comp) in winlist: win = "user" else: win = "computer" return win Step #4: Get computer choice Given the three objects in the sequence things, choose randomly. This leads to [rps-prog2.py]:
def getcomp(): pick = random.choice(things) print("Computer picks", pick) return pick Step #5: Get user input Loop until you get a valid input. If the user types an end of file (control-d) or an interrupt (control-c), act as though the user typed “quit”; report any other exceptions and then act as though the user typed “quit”.
This leads to [rps-prog3.py]:
def getuser(): while True: try: n = input("Human: enter rock, paper, scissors, quit: ") except (EOFError, KeyboardInterrupt): n = "quit" break except Exception as msg: print("Unknown exception:", msg, "-- quitting") n = "quit" break *** check input *** return n To check input, we need to be sure it’s a valid command, so see if it’s in cmdlist:
if n not in cmdlist:
print("Bad input; try again")
else:
break
Put these together to get the user input routine.
Feel free to reach out if any issues 🙌