Question

Repl.it

Python

Ch 07 #5: Rock, Paper, Scissors Modification

Programming Exercise 11 in Chapter 6 asked you to design a program that plays the Rock, Paper, Scissors game. In the program, the user enters one of the three strings - “rock”, “paper”, or “scissors” - at the keyboard. Add input validation (with a case-insensitive comparison) to make sure the user enters one of those strings only.

I demonstrated the implementation of the program here: https://repl.it/@profeldridge/week06assignment06part2of2#main.py

Using the repl.it link above, modify the program to implement a new function called “get_user_input_validated()” that performs input validation (with a case-insensitive comparison) to make sure the user enters one of those strings only.

Requirements

You must use the given function prototypes. You can add more functions if you like.

def get_user_input_validated()

Resources

• Use the same logic and text that you used for the flowchart

• The Python Survival Guide shows how to make a string lowercase: https://lrccd.instructure.com/courses/102062/discussion_topics/1168996

Example Runs:

Please enter your choice (rock/paper/scissors):

rocks

Sorry - that selection is not valid. Please enter the text 'rock', 'paper', or 'scissors'

peppers

Sorry - that selection is not valid. Please enter the text 'rock', 'paper', or 'scissors'

ROCK

Human: [ rock ] vs. Computer: [ paper ]

Sorry! You lost

Deliverables

1. Source Code File: Name your file main.py and submit to Canvas.

Be sure to follow a Python Style Guide:

• Recommended (v2.0) https://lrccd.instructure.com/courses/102062/modules/items/5357574

Original (v1.0) https://lrccd.instructure.com/courses/102062/pages/python-code-style-guide?module_item_id=5176726

Answer 1

<<<<<<<<<<<< python code >>>>>>>>>>>

"""

Program Name: Rock, Paper, Scissors Game

Filename: main.py

Author: Professor Eldridge

Date: 2020-09-21

Assignment: Lecture Demo

Description: Book Programming Exercise #11

Sources: See https://lrccd.instructure.com/courses/102062/pages/python-code-style-guide

"""

from random import *

ROCK_INT = 1

PAPER_INT = 2

SCISSORS_INT = 3

ROCK_STR = "rock"

PAPER_STR = "paper"

SCISSORS_STR = "scissors"

def get_user_input_validated():

choice=["rock","paper","scissors"]

while True:

user_choice = input("Please enter your choice (rock/paper/scissors):")

if user_choice.lower() in choice:

break

else:

print("Sorry - that selection is not valid.",end="")

return user_choice.lower()

def convert_raw_to_const(raw_number):

"""

Module Name: convert_raw_to_const

Parameters: int -> raw_number is an integer between 1-3 (inclusive)

Description: Given an integer, return the corresponding description of rock, paper, scissors

"""

result = ""

if (raw_number == ROCK_INT):

result = ROCK_STR

elif (raw_number == PAPER_INT):

result = PAPER_STR

elif (raw_number == SCISSORS_INT):

result = SCISSORS_STR

else:

print("Error! Unknown raw_number:", raw_number)

return result

def compare_choices(human, computer):

"""

Module Name: compare_choices

Parameters: Two strings -> human choice and computer choice of "rock, paper, or scissors"

Description: Given the two choices, use the rules of the game to identify the outcome

"""

result = 0

if (human == computer):

result = 0

elif (human == ROCK_STR and computer == SCISSORS_STR or

human == SCISSORS_STR and computer == PAPER_STR or

human == PAPER_STR and computer == ROCK_STR):

# This block is the essential rules of the game

result = 1

else:

# Short cut: assume if not a tie & human didn't win, then computer won

result = -1

return result

def main():

"""

Module Name: main

Parameters: None

Description: Program entry point. Provides the program flow of execution

"""

# The game doesn't end if the outcome is a tie

keep_playing = True

while (keep_playing):

# Random choice of 1-3

computer_choice_raw = randint(1,3)

# Convert the random choice into a constant that can be compared with

# the user's choice

computer_choice = convert_raw_to_const(computer_choice_raw)

user_choice=get_user_input_validated()

print("Human: [", user_choice, "] vs. Computer: [", computer_choice,"]")

# Following standard rules of comparison, evaluate the human & computer choices

outcome = compare_choices(user_choice, computer_choice)

if (outcome == 0):

print("Tie! You will play again until there is a winner")

keep_playing = True

elif (outcome == 1):

print("Congratulations! You won")

keep_playing = False

elif (outcome == -1):

print("Sorry! You lost")

keep_playing = False

else:

print("Error! Unknown outcome:", outcome)

keep_playing = False

main()

<<<<<<<<<<<<< sample run and changes >>>>>>>>>>

def get_user_input_validated():

choice=["rock","paper","scissors"]

while True:

user_choice = input("Please enter your choice (rock/paper/scissors):")

if user_choice.lower() in choice:

break

else:

print("Sorry - that selection is not valid.",end="")

return user_choice.lower()

change in main()

sample result

<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>