Mini-project description — Rock-paper-scissors-lizard-Spock
Rock-paper-scissors is a hand game that is played by two people. The players count to three in unison and simultaneously "throw” one of three hand signals that correspond to rock, paper or scissors. The winner is determined by the rules:
- Rock smashes scissors
- Scissors cuts paper
- Paper covers rock
Rock-paper-scissors is a surprisingly popular game that many people play seriously (see the Wikipedia article for details). Due to the fact that a tie happens around 1/3 of the time, several variants of Rock-Paper-Scissors exist that include more choices to make ties less likely.
Rock-paper-scissors-lizard-Spock (RPSLS) is a variant of Rock-paper-scissors that allows five choices. Each choice wins against two other choices, loses against two other choices and ties against itself. Much of RPSLS‘s popularity is that it has been featured in 3 episodes of the TV series "The Big Bang Theory". The Wikipedia entry for RPSLS gives the complete description of the details of the game.
In our first mini-project, we will build a Python function rpsls(name) that takes as input the string name, which is one of "rock", "paper","scissors", "lizard", or "Spock". The function then simulates playing a round of Rock-paper-scissors-lizard-Spock by generating its own random choice from these alternatives and then determining the winner using a simple rule that we will next describe.
While Rock-paper-scissor-lizard-Spock has a set of ten rules that logically determine who wins a round of RPSLS, coding up these rules would require a large number (5x5=25) of if/elif/else clauses in your mini-project code. A simpler method for determining the winner is to assign each of the five choices a number:
- 0 — rock
- 1 — Spock
- 2 — paper
- 3 — lizard
- 4 — scissors
In this expanded list, each choice wins against the preceding two choices and loses against the following two choices (if rock and scissors are thought of as being adjacent using modular arithmetic).
In all of the mini-projects for this class, we will provide a walk through of the steps involved in building your project to aid its development. A template for your mini-project is available here. Please work from this template.
http://www.codeskulptor.org/#user40_8h6EmKBtPG3oWfv_0.py
# Rock-paper-scissors-lizard-Spock template
# The key idea of this program is to equate the strings
# "rock", "paper", "scissors", "lizard", "Spock" to numbers
# as follows:
#
# 0 - rock
# 1 - Spock
# 2 - paper
# 3 - lizard
# 4 - scissors
# helper functions
def name_to_number(name):
# delete the following pass statement and fill in your code below
if(name == "rock"):
return 0
elif(name == "Spock"):
return 1
elif(name == "paper"):
return 2
elif(name == "lizard"):
return 3
elif(name == "scissors"):
return 4
else:
return "error"
# convert name to number using if/elif/else
# don‘t forget to return the result!
def number_to_name(number):
# delete the following pass statement and fill in your code below
if(number == 0):
return "rock"
elif(number == 1):
return "Spock"
elif(number == 2):
return "paper"
elif(number == 3):
return "lizard"
elif(number == 4):
return "scissors"
else:
return "error"
# convert number to a name using if/elif/else
# don‘t forget to return the result!
def rpsls(player_choice):
# delete the following pass statement and fill in your code below
# print a blank line to separate consecutive games
print ""
# print out the message for the player‘s choice
print "Player chooses",player_choice
# convert the player‘s choice to player_number using the function name_to_number()
player_number = name_to_number(player_choice)
# compute random guess for comp_number using random.randrange()
import random
comp_number = random.randrange(0, 5)
# convert comp_number to comp_choice using the function number_to_name()
comp_choice = number_to_name(comp_number)
# print out the message for computer‘s choice
print "Computer chooses", comp_choice
# compute difference of comp_number and player_number modulo five
diff = comp_number - player_number % 5;
# use if/elif/else to determine winner, print winner message
if (diff == -3 or diff == -4 or diff == 1 or diff == 2):
print "Computer wins!"
elif (diff == 3 or diff == 4 or diff == -1 or diff == -2):
print "Player wins!"
elif (diff == 0):
print "Player and computer tie!"
else:
print "error"
# test your code - THESE CALLS MUST BE PRESENT IN YOUR SUBMITTED CODE
rpsls("rock")
rpsls("Spock")
rpsls("paper")
rpsls("lizard")
rpsls("scissors")
# always remember to check your completed program against the grading rubric