PE4.py

from random import random

# volleyball.py
# this time use rally scoring: both server or non-server get the score when win the rally

def main():
    printlntro ()
    probA, probB, n = getlnputs()
    winsA, winsB = simNGames(n, probA, probB)
    printSummary(winsA, winsB)

def printlntro():
    print("This program simulates a game of volleyball between two")
    print('teams called "A" and "B", using rally scoring. ')
    print('The ability of each player is')
    print("indicated by a probability (a number between 0 and 1) that")
    print("the team wins the point when serving. Team A always")
    print("has the first serve.")

def getlnputs():
    # Returns the three simulation parameters
    a = float(input("What is the prob. Team A wins a serve? "))
    b = float(input("What is the prob. Team B wins a serve? "))
    n = int(input("How many games to simulate? "))
    return a, b, n

def simNGames(n, probA, probB):
    winsA = winsB = 0
    for i in range(n):
        scoreA, scoreB= simOneGame(probA, probB)
        if scoreA > scoreB:
            winsA = winsA + 1
        else:
            winsB = winsB + 1
    return winsA, winsB

def simOneGame(probA, probB):
    serving = "A"
    scoreA = 0
    scoreB = 0
    while not gameOver(scoreA, scoreB):
        if serving == "A" :
            if random() < probA:
                scoreA = scoreA + 1
            else:
                serving = "B"
                scoreB = scoreB + 1
        else:
            if random() < probB:
                scoreB = scoreB + 1
            else:
                serving = "A"
                scoreA = scoreA + 1
    return scoreA, scoreB

def gameOver(a, b):
    # a and b represent scores for a volleyball game
    # Returns True if the game is over, False otherwise.
    return (a>= 25 or b>= 25) and ((a-b > 2) or (b-a > 2))

def printSummary(winsA, winsB):
    # Prints a summary of wins for each team, using two scoring system
    n = winsA + winsB
    print("\nGames simulated: ", n)
    print("Wins for A: {0} ({1: 0.1%})".format(winsA, winsA/n))
    print("Wins for B: {0} ({1: 0.1%})".format(winsB, winsB/n))

main()